Updated at 8:23 p.m. ET
(CBS/AP) TOULOUSE, France - Riot police set off explosions outside an apartment building early Thursday in an effort to force the surrender of a gunman who boasted of bringing France "to its knees" with an al Qaeda-linked terror spree that killed seven people.
Hundreds of heavily armed police, some in body armor, cordoned off the five-story building in Toulouse where the 24-year-old suspect, Mohamed Merah, had been holed up since the pre-dawn hours.
As midnight approached, three explosions were heard and orange flashes lit up the night sky near the building.
Authorities said the shooter, a French citizen of Algerian descent, had been to Afghanistan and Pakistan, where he claimed to have received training from al Qaeda.
They said he told negotiators he killed a rabbi and three young children at a Jewish school on Monday and three French paratroopers last week to avenge the deaths of Palestinian children and to protest the French army's involvement in Afghanistan, as well as a government ban last year on face-covering Islamic veils.
"He has no regrets, except not having more time to kill more people and he boasts that he has brought France to its knees," Paris Prosecutor Francois Molins told a news conference.
The standoff began when a police attempt at around 3 a.m. to detain Merah erupted into a firefight. Three police were wounded, triggering on-and-off negotiations with the suspect that lasted into the night.
As darkness fell, police cut electricity and gas to the building, then quietly closed in to wait out the suspect.
Authorities were "counting on his great fatigue and weakening," said Didier Martinez of the SGP police union, adding the siege could go on for hours. Street lights were also cut, making Merah more visible to officers with night vision goggles in case of an assault.
French authorities -- like others in Europe -- have long been concerned about "lone-wolf" attacks by young, Internet-savvy militants who self-radicalize online since they are harder to find and track. Still, it was the first time a radical Islamic motive has been ascribed to killings in France in years.
Merah espoused a radical brand of Islam and had been to the Afghanistan-Pakistan region twice and to the Pakistani militant stronghold of Waziristan for training, Molins said.
He said the suspect had plans to kill another soldier, prompting the police raid.
The gunman's brother and mother were detained early in the day. Molins said the 29-year-old brother, Abdelkader, had been implicated in a 2007 network that sent militant fighters to Iraq, but was never charged.
The police raid Wednesday was part of France's biggest manhunt since a wave of terrorist attacks in the 1990s by Algerian extremists. The chase began after France's worst-ever school shooting Monday and two previous attacks on paratroopers, killings that have horrified the country and frozen the campaigning for the French presidential election next month.
French President Nicolas Sarkozy has played up nationalist themes in his bid for a second term.
"Terrorism will not be able to fracture our national community," Sarkozy declared Wednesday on national television before heading to funeral services for two paratroopers killed and another injured in Montauban, near Toulouse.
Sarkozy met with local Jewish leaders earlier Wednesday and told them the police would only storm the building if there was an immediate threat that he'd blow up himself or the building and authorities are satisfied for now that he is not prepared to do so, reports CBS Radio News correspondent Elaine Cobbe.
The suspect repeatedly promised to turn himself in Wednesday, then halted negotiations. Cedric Delage, regional secretary for a police union, said police were prepared to storm the building if he did not surrender.
After bouts of deadly terrorist attacks in France in the 1980s and 1990s, France beefed up its legal arsenal -- now seen as one of the most effective in Western Europe and a reference for countries including the U.S. after the Sept. 11 attacks.
Sarkozy's office said President Barack Obama called him Wednesday to express condolences to the families of the victims and praise French police for tracking down the suspect. The statement said France and the United States are "more determined than ever to fight terrorist barbarity together."
In recent years, French counterterrorism officials have focused mainly on al Qaeda in the Islamic Maghreb, the North African affiliate of Osama Bin Laden's network that has its roots in an insurgent group in Algeria, a former French colony.
Molins said Merah's first trip to Afghanistan ended with him being picked up by Afghan police "who turned him over to the American army who put him on the first plane to France."
"He had foreseen other killings, notably he foresaw another attack this morning, targeting a soldier," Molins said, adding also planned to attack two police officers. "He claims to have always acted alone."
Mohammed Merah has a long record as a juvenile delinquent with 15 convictions, Molins added.
An Interior Ministry official, speaking on condition of anonymity, said Merah had been under surveillance for years for having "fundamentalist" Islamic views.
Christian Etelin, a lawyer who previously represented Merah in France regarding other legal matters, described Merah as "polite and courteous" to French media outlet BFMTV. He said that he "absolutely" did not espouse extremist views in his presence, "but I learned two years ago that he was suddenly radicalized and had gone to Afghanistan."
There was some confusion over the suspect's background. The commander of the prison in Kandahar, Afghanistan, Col. Ghulam Farouq, tells CBS News they had a prisoner by the name of Mohammad Merah of north African origin who was arrested in 2008 in connection with a bombing in Kandahar and sentenced to three years. He managed to escape later that year, along with about 600 other prisoners, in a brazen prison break staged by the Taliban.
But it's unclear if the suspected shooter is in fact the Merah who escaped the prison. Kandahar provincial spokesman Ahmad Jawed Faisal said their records also show that Merah was an Afghan citizen from Kandahar province.