French police have reportedly stormed the house of Mohammed Merah, the suspect in a series of shootings in the south-west region of France, which left seven people dead.
Three explosions were heard close to the block of flats where the man has been holed up for more than 20 hours. The blasts reportedly blew out the doors at the front of the apartment.
However, a conflicting report from the French Interior Ministry said that the explosions were simply an "intimidation tactic" and that an assault is not underway.
The man is believed to still be inside the building.
The blasts rang out shortly before 11pm (GMT). Following the explosions, the city's deputy mayor, Jean-Pierre Havrin, said that an assault "had started".
The suspected gunman at the centre of the siege had said that he would surrender late Wednesday evening.
French BFM TV had earlier reported his arrest had taken place, but that was denied by Interior Minister Claude Gueant.
"The negotiations continue. They are still under way," Gueant said.
About about 300 police, some wearing body armour, surrounded the four-storey building at around 3am on Wednesday.
Two police officers were injured in the raid after shots were fired. One was shot in the knee, said officials, and another was "lightly injured".
Speaking to French media, a former member of the police Raid unit said the initial operation had been bungled.
Gueant said that the man had earlier thrown one weapon out of a window in exchange for a phone, but still had several arms including an Uzi and a Kalashnikov rifle.
For more than two hours the suspect cut off contact with police, despite swapping one of his weapons for a mobile phone.
Contact only resumed at about 1.30pm French time.
The 24-year-old suspect, named by police as French national Mohammed Merah, who is of Algerian extraction, is said to be acting 'in revenge for Palestinian children' and has claimed to belong to a fringe group related to al-Qaeda.
More to follow...