There are reports another two short blasts have been detonated in Toulouse, at the scene of a standoff with an armed serial killer.
Mohammed Merah is armed and has already wounded two police officers.
Witnesses at the scene say police are doing everything they can to ensure the suspect is unable to relax.
It remains unclear whether it's Merah shooting, or if an assault is underway.
The French Government says police are not attempting to the storm the home of suspected serial killer Mohammed Merah.
Reports of a raid spread after three explosions were heard near the suspect's apartment in Toulouse.
The Toulouse Deputy Mayor had also confirmed the attack.
However the Interior Ministry has contradicted the deputy mayor and has clarified what's happening.
It says the explosions were an attempt to encourage Merah to surrender after he changed his mind about earlier plans to give himself up.
Police had just an hour earlier turned off the lights in nearby streets around the apartment in Toulouse where a suspected serial killer is holed up.
Mohamed Merah has been holed up in his apartment after a pre-dawn raid (around 3pm yesterday NZ time) and is surrounded by 300 police.
The suspect said he'll come out but he hasn't and police want the standoff to end.
CNN's Diana Magnay says he's heavily armed and police have been in negotiations with him throughout the siege.
"What his terms are we really don't know at this stage but they said that they didn't want this sort of impasse continue into the night time hours because that night fall will make the operation that much harder," she told Newstalk ZB's Mike Hosking.
Diana Magnay says some of his motives have emerged - he's angry that France has banned the wearing of the Muslim veil, and wanted to kill Jewish children in revenge for the deaths of Palestinian children.
She says police matched his profile with CCTV footage, and from previous offences knew of him and his militant brother.
But she says the key breakthrough was the Yamaha motor scooter used in all three crime scenes.
"The garage owner had alerted the police that one of the Merah brothers had come to him and asked how to repaint his scooter and how to remove the GPS tracking device from it so that it couldn't be located."
Newstalk ZB's Europe correspondent Catherine Field says the suspect has 15 convictions and has served time in a juvenile detention centre.
"Other bits of his background are emerging, some of it contradictory but what we do know is he made two trips to the lawless areas of Pakistan and Afghanistan, we don't know whether he had combat experience there," she told Mike Hosking
Since returning he's been under surveillance by French domestic intelligence services, but they say there was nothing in his behaviour to suggest he'd come to the point of committing a criminal act.
Merah belongs to an extremist group called Knights of Glory which was banned by the French Government in January.
But a Paris prosecutor says he acted alone.
Francois Molins says he shows no remorse, and has told them he planned to bring France to its knees.
"Police tried to force down the door. Mr Mohammed Merah opened fire on the police and one was wounded in the knees, another was slightly wounded."
CNN's John Defterious says he's armed with a machine gun and pistols.
"He says he belongs to al Qaeda, was trained in Pakistan and Afghanistan, and described himself as a martyr on behalf of those killed in Pakistan and Afghanistan and in fact, prosecutors said today that he planned to kill at least one other soldier, he was set free."
His mother, who is from Algeria, was brought to the scene but has refused to reason with him, saying she has little control over him.
Photo: Police surround Mohammed Merah's house (Getty Images)