WATCH: Who Was Abdelhamid Abaaoud? The Mastermind of the Paris Terror Attacks

SAINT DENIS, France - A woman suicide bomber blew herself up and another militant died on Wednesday when police raided an apartment in the Paris suburb of St. Denis seeking suspects in last week's attacks in the French capital.

Officials said police had been hunting Abdelhamid Abaaoud, a Belgian Islamist militant accused of masterminding the Nov. 13 carnage, but more than seven hours after the launch of the pre-dawn raid it was still unclear if they had found him.

Seven people were arrested in the operation, which started with a barrage of gunfire, including three people who were pulled from the apartment, officials said.

"It is impossible to tell you who was arrested. We are in the process of verifying that. Everything will be done to determine who is who," Paris prosecutor Francois Molins said at the end of the operation.

Molins said the assault was ordered after phone taps and surveillance operations led police to believe that Abaaoud might have been in St. Denis, near to the soccer stadium which was site of one of the attacks that hit Paris last week.

A total of 129 people died in the coordinated bombings and shootings. Investigators believe the worst atrocity in France since World War Two was set in motion from Syria, with Islamist cells in neighbouring Belgium organising the mayhem.

Two police sources say investigators believe the St. Denis group had been planning an attack on the French capital's La Defense business capital.