WHAT WE KNOW
• State of emergency declared in Christchurch and Selwyn.
• 11 homes and two sheds destroyed.
• Four casualties: Pilot dead while fighting fires, two treated in hospital after inhaling smoke and one with an injured ankle
• 1000 people evacuated from 450 houses.
• Spread across more than 2075 hectares.
• More than 390 firefighters have been battling the flames on the ground today - including 26 rural fire crews with more than 200 personnel between them. The Fire Service has 62 crews with 190 pumps and tankers and more than 160 firefighters on the ground.
• First fire began on Monday, along Early Valley Road In Lansdowne, with a second blaze on Marley's Hill in a carpark off Summit Rd
• Evacuation centres: The Nga Hau e Wha Marae Pages Rd, Te Hapua Halswell Centre, Halswell Rd
• Weather for the region tomorrow: Cloudy with occasional drizzle from the evening on Friday, a high of 21C. Average wind speeds of up to 28km/h. Saturday: Occasional rain or drizzle, with northeasterly winds continuing.
• Several roads closed/cordoned off.
• 128 customers without power in the Port Hills.
• Three schools closed: Cashmere Primary School, Cashmere Early Learning Centre and Kidsfirst Kindergarten in Cashmere are all closed today.
• A health warning has been issued for anyone suffering respiratory issues to contact their GP.
• The Government has accepted help from United States research vessel, Polar Star, currently in Lyttelton Harbour.
• Australia also now on board, with an Air Force C-130 Hercules aircraft travelling there today to collect five pallets of firefighting foam and other fire-retardant materials.
• A detachable fire pod is being shipped from Wellington tonight and will add to the four NZ Defence Force pods being used to shoot high-pressure water in the ground to extinguish roots burning below the surface
• 14 helicopters and three fixed-wing aircraft made up the crew battling flames from the air on Thursday.
• Cordons to remain in place and overnight, with police and Defence Force staff patrolling.
Listen live to Newstalk ZB for the latest updates.
UPDATED 11.51pm Eleven homes have been destroyed as firefighters continue to battle a fire that has been burning in Christchurch's Port Hills for more than three days.
Close to 400 firefighters, 190 pumps and tankers, 14 helicopters and three planes have been tackling the blaze, which has spread through more than 2075 hectares and also claimed two sheds.
Southern Fire Communications' shift manager, Riwai Grace, said at 11.30pm they still had 13 fire trucks and tankers and their crews fighting the fire tonight.
A couple of hot spots had flared up in the Westmorland, Hoon Hay Valley and Kennedys Bush areas, but they had been dealt with quickly and were being monitored overnight, Grace said.
Speaking from Christchurch, Newstalk ZB reporter Georgina Campbell said there have been no further evacuations tonight and the fire is currently "simmering on the hillside".
Worried residents have been told that a large number of houses are expected to have been damaged by smoke, heat and fire.
Christchurch Civil Defence controller Dave Adamson says the total number of properties affected won't be known until the emergency has ended.
"We are aware that this is an extremely anxious time for residents who have had to leave their homes," he said.
"We're working with other agencies to arrange for this information to be passed on to home owners in the affected areas as soon as the information becomes available."
LISTEN ABOVE: NEWSTALK ZB REPORTER MATIU WORKMAN UPDATES MARCUS LUSH
Significant rain is not expected until Saturday, but there are hopes that a predicted change in wind direction on Friday will slow the progress of the fire.
Emergency services are preparing to continue operations over the weekend at least, with the emphasis being to direct the flames away from people and property.
Extinguishing the fire, which began in two separate locations on Monday night before merging on Wednesday night, could take much longer.
"This fire has got to be got under control," Christchurch mayor Lianne Dalziel said.
"It's going to take weeks because it's going to smoulder. There are going to be outbreaks from time to time.
"The wind could change while we are speaking and that would make a difference."
A state of emergency has been in force in Christchurch and Selwyn District since Wednesday.
Residents of 400 homes have been evacuated by police, who have 50 staff working around the clock in response to the fires.
Hundreds of other residents have chosen to self-evacuate.
Police have warned that situation is extremely volatile and people may have to leave at short notice if the fire changes direction.
Meanwhile, another 25 Defence Force personnel have joined 36 colleagues working with emergency services, and an Air Force C-130 Hercules has headed to Australia to collect fire retardant.
Prime Minister Bill English said crews from the US Coastguard ship Polar Star had been assisting, and offers of help from Australian firefighters were also being considered.
Speaking during a visit to Christchurch, Mr English said he had been told the situation was "contained but not controlled".
He added that the cause of the fire appeared to be suspicious.
"I've only had a very brief description of the fire starting in two places at about the same time which, to someone like me, looks a bit suspicious," Mr English said after viewing the area from a helicopter.
"I wouldn't want to jump to conclusions but that seems a bit odd."
Investigations are still underway to confirm the cause of the blaze. Fire investigator Ken Legat said a team of four have spent the last two days in the Early Valley Road area trying to determine the cause of the fire.
"We've identified an area of origin, or an area of interest, but at this stage we're still trying to determine a cause," Legat said.
He said the "area of interest" measures just one and a half square metres and his team are calling on any witnesses who took footage of either of the fires when they first started.
Mr English met with a number of firefighters who have been battling the blaze and say while they look tired they were confident in their training and teamwork.
Civil Defence Minister Gerry Brownlee praised those on the ground for their efforts and the huge amount of "goodwill" that came from them giving up their time and putting their lives on the line.
His visit came a day after he questioned the emergency response to the blaze, including why a state of emergency wasn't called sooner. "I think the most accurate advice I was getting yesterday came from the media," he said.
He didn't lay blame on the rural fire services, firefighters or volunteers who who were in charge of the blaze at the time, rather said it was a legislative issue.
"I don't want any suggestion out there from me that they've been doing anything other than an amazing job. These are very brave people doing a great job, there's no question about that," he said.
"It's structures inside the legislative arrangements that fall to politicians to fix and we've got to fix it."
Labour says Mr Brownlee should have called a state of emergency himself, allowing fire services to commandeer resources as soon as they were needed.
He agreed that was true, but said doing so required full knowledge of the scene, and there are structures in place for those with that information to make the decision that need to be fixed in future.
Containing and controlling the fire could take days or a week and going back through the process is something for another day, Mr English said.
"What's important now is the ongoing containment, hope that the weather stays right and that the people who are affected have the support of the community because some of them have lost their houses and their life savings," he said.
About a dozen residents spent the day at Te Hapua Halswell Centre and the Nga Hau e Wha Marae, with an evacuation Facebook page set up to offer housing to others.
Winds were gusting at 48 kilometres per hour at Sugarloaf hill at times on Thursday, according to the MetService.
Cashmere Primary School, Cashmere Early Learning Centre and Kidsfirst Kindergarten were closed on Thursday.
About 120 homes were without power through Thursday, but many of those were in the evacuation zone, power network company Orion said.
Firefighters have managed to keep the blaze away from the newly opened Christchurch Adventure Park and the historic Sign of the Kiwi cafe.
While the network was holding up well, there was still a risk of further cuts, following a large-scale outage on Wednesday, it said.
A health warning has been issued for residents in Christchurch who may have health conditions, as smoke billows over the city.
One firefighter was taken to hospital with smoke inhalation but has been released and a child was also brought in with smoke-related breathing problems, according to Christchurch Hospital.
The blaze, which started as two separate fires on Monday and which sparked a local Civil Defence state of emergency, was fanned by wind change, merged into one on Wednesday night, Civil Defence said.
Former SAS soldier Steve Askin, 38, died when the Squirrel helicopter he was flying crashed while battling the blaze on Tuesday.
• Worsley Rd
• Hoon Hay Rd from Cashmere Rd
• Kennedys Bush Rd from Cashmere Rd
• Dyers Pass Rd from Sign of the Takahe
• Early Valley Rd
• Cashmere Rd west of Kaiwara St to Kennedys Bush Rd.
• Worsleys Rd
• Hoon Hay Valley Rd
• Kennedys Bush Rd from the roundabout with Rock Hill Drive. This includes the southbound cycle track
• Worsleys Track from Worsleys Rd
• Dyers Pass Rd between Hackthorne Rd to Governors Bay Rd. Use the Lyttelton Tunnel or Gebbies Pass as the alternative route
• Summit Rd between Gebbies Pass and Rapaki Track
• Old Tai Tapu Rd between Osterholts Rd and Early Valley Rd
• Early Valley Rd
• Holmes Rd
Around 128 customers remain without power in the Port Hills area.
Electricity has been maintained throughout the rest of Christchurch, while lines in the fire-affected area are still off grid.
Orion is asking businesses and residents to conserve power wherever possible, to reduce the load on the network.
People have been told to stay inside to avoid smoke inhalation.
Dr Alistair Humphrey, Canterbury Medical Officer of Health has advised that anyone suffering respiratory issues contact their GP.
"For the vast majority of people, the smoke will be unpleasant, but carries no risk to their health. However, smoke may irritate the eyes, nose, throat and airways. More serious symptoms include runny or sore eyes, dry or sore throat, sore nose, cough, tightness of the chest or difficulty breathing.
"In healthy people, most symptoms disappear soon after exposure to smoke ends and do not cause long-term health problems."
Cigarette smokers, the elderly, children and those with heart disease, asthma or other lung disease are at greatest risk of harm from smoke inhalation.
"Avoid exposure where possible by staying indoors and closing windows and doors," he says.