TOULOUSE, France - French police started an assault late on Wednesday on the apartment of a gunman suspected of killing seven people in southwest France in the name of al Qaeda, officials said.

Three loud blasts were heard at the site just before midnight, which blew open the door of the apartment where the gunman had been holed up since 3 a.m. (0200 GMT), a police source said.

"I confirm that the assault has started," a police source told Reuters. The deputy mayor of Toulouse Jean-Pierre Havrin confirmed that negotiations had ended and the assault had begun.

Police had been trying to get 24-year-old Mohamed Merah to turn himself over after he fired through the door at them while they tried to storm his apartment in the suburbs of Toulouse in the early hours of Wednesday morning.

An undated and non-datelined video frame grab broadcast March 21, 2012 by French national television station France 2 who they claim to show Mohamed Merah. [Photo/Agencies]