The man in Monday's attack in Toulouse is suspected to have neo-Nazi ties or grudges against minorities. The suspect first gunned down a rabbi and his two young sons, then chased down a young girl, shooting her at point-blank range.
Authorities say the gunman may also be behind a recent attack on French paratroopers that left three soldiers dead. The victims were of North African and French Caribbean backgrounds.
The Associated Press reported early Wednesday morning Toulouse time that French police raided a house in Toulouse in the search for the gunman.
The AP reported French police officers exchanged gunfire and were negotiating with a man who claims connections to al-Qaida and is suspected of killing three Jewish schoolchildren, a rabbi and three paratroopers in three attacks.
French Interior Minister Claude Gueant said three police officers were injured in the raid on a house in the southern city of Toulouse.
Gueant said the man is 24 years old, of French nationality and says that "he belongs to al-Qaida." He says the suspect "wants to take revenge for Palestinian children" killed in the Middle East, and is angry at the French military for its operations abroad.
Gueant says the man's brother was arrested.
Tuesday, President Nicolas Sarkozy vowed to bring the suspect to justice, calling him a "monster" on the loose in France.
"There are beings who have no respect for life. When you grab a little girl to put a bullet in her head, without leaving her any chance, you are a monster. An anti-Semitic monster, but first of all a monster," he said.
Schools across the country held a moment of silence in honor of the victims, who were heading to Israel for burial. It was the deadliest school shooting in the country and the bloodiest attack on Jewish targets in decades.
Officials say the suspect may have filmed the shootings. According to Interior Minister Claude Gueant, the attacker was seen wearing a camera around his neck that could be used to film and post video online.
France has western Europe's largest population of both Jews - about half a million - and Muslims - about 5 million.
The Associated Press contributed to this report.
