Authorities in France on Friday were investigating whether or not the Islamic radical responsible for the murders of Jewish school children had acted alone or was supported by al Qaeda, after a little-known extremist group claimed responsibility for the attacks.

Mohamed Merah was killed by police on Thursday after a 32-hour siege of his apartment building in the southwestern city of Toulouse. Merah was shot in the head as he tried to jump out of a window in a blaze of gunfire, according to police.

The 23-year-old French citizen of Algerian origin had shot dead three soldiers earlier in the month and killed three children and a teacher at a Jewish school on Monday. Merah claimed to have received training from al Qaeda in Afghanistan and the militant stronghold of Waziristan in Pakistan.

The obscure Islamist group Jund al-Khilafah issued a statement claiming responsibility for the attacks, referring to Merah as "Yusuf of France," according to the SITE Intelligence Group, which monitors Jihadist websites. The claim could not be independently confirmed.

Merah said he launched the attacks to avenge Palestinian deaths and punish France for its military presence in Afghanistan, according to prosecutor Francios Molins. The French prosecutor said that Merah had filmed all three attacks.

"You killed my brother, I kill you," he said in a video of the first attack, in which one French paratrooper died.

Flagged by authorities

Merah's travels to Afghanistan and Pakistan were known to French intelligence prior to the shootings and he had been on a US no-fly list since 2010, which prohibited him from boarding any flight to America. He also had a record of pretty crime in France and was reportedly radicalized while serving time in prison.

French prosecutor Molins said that Merah had on one occasion been arrested by Afghan police and handed over to US troops during a trip to the region.

"One can ask the question whether there was a failure or not," French Foreign Minister Alain Juppe said on Europe 1 radio. "We need to bring some clarity to this."

Police said that Merah's mother, brother and his brother's girlfriend had been detained as part of the investigation. Merah's 29-year-old brother, Abdullah, had reportedly been linked to Iraqi Islamist networks.

French President Nicolas Sarkozy, meanwhile, has vowed to crackdown on anyone who goes abroad "for the purposes of indoctrination in terrorist ideology." Sarkozy also cautioned against blaming France's five-million strong Muslim community for the attacks.

"Our Muslim compatriots had nothing to with the crazy motive of a terrorist," said the French president, noting that Muslim paratroopers were among those killed.

slk/pfd (AP, AFP)