An urgent notice has been issued to residents in East Christchurch to boil their water until further notice after samples showed bacteria “contamination”.

An alert has been sent to hundreds of cellphones and posted on Christchurch City Council social media.

The alert sent to phones in Christchurch.

“Residents and visitors to areas of New Brighton, Burwood, Wainoni, Aranui and Southshore are being advised to boil their water until further notice after a sample within the zone was found to be contaminated,” it said.

“Testing in the area showed the presence of bacteria in drinking water which means it is unsafe to drink.

“All water used for drinking, food preparation, utensil washing, brushing teeth or making ice should be boiled until further notice.”

Hundreds of people have received an alert to their phone about the situation and the council has posted information online.

The council assured residents that staff and contractors are in the area undertaking further testing and investigations are under way to understand the cause of the contamination.

“Until we have further information the boil water notice will remain in place,” it said.

“Bringing water to the boil is sufficient to kill bugs. If you can’t boil your water then bottled water is the only other option.”

The council said the text alerts went to residents’ cellphones - but would also be received by people travelling into the affected areas.

“Residents are encouraged to share the message with their neighbours,” it said.

“The boil water notice will be in place until further notice.”

One resident shopping in New World Stanmore said people were flooding into the drinks aisle to buy bottled water. They said customers could be heard openly discussing the boil water notice.

Customers in New World Stanmore have been stocking up on bottled water.