French warplanes pounded Islamic State positions in Syria on Sunday as police in Europe widened their investigations into coordinated attacks in Paris that killed more than 130 people.

Islamic State has claimed responsibility for Friday's suicide bombings and shootings, which have re-ignited a row over Europe's refugee crisis and drawn calls to block a huge influx of Muslim asylum-seekers.

French police have launched an international hunt for a Belgian-born man they believe helped organize the assaults with two of his brothers. One of the brothers died in the attacks, while the second one is under arrest in Belgium, a judicial source said.

A further two French suicide attackers have been identified, police said, while the identity of four other assailants, who all died in the violence, was still under review.

France has been bombing Islamic State positions in Iraq and Syria for months as part of a U.S.-led operation. Following Friday's mayhem, Paris vowed to destroy the group. Underlining its resolve, French jets on Sunday launched their biggest raids in Syria to date, hitting its stronghold in Raqqa.

"The raid ... including 10 fighter jets, was launched simultaneously from the United Arab Emirates and Jordan. Twenty bombs were dropped," the Defence Ministry said. Among the targets were a munitions depot and training camp, it said.

There was no word on casualties or the damage inflicted.

The investigation into Friday's attacks, the worst atrocity in France since World War Two, led swiftly to Belgium after police discovered that two of the cars used by the Islamist militants had been rented in the Brussels region.

SEVEN HELD IN BELGIUM

By Sunday, Belgian officials said they had arrested seven people in Brussels. But one of the people who had hired the cars slipped through the fingers of the police. He was pulled over on the French-Belgian border on Saturday, but later released.

Police named the man they were seeking as Salah Abdeslam, saying the 26-year-old was "dangerous". Although he was born in Brussels, French authorities said he was a French national.

"The abject attacks that hit us on Friday were prepared abroad and mobilized a team in Belgium that benefited ... from help in France," French Interior Minister Bernard Cazeneuve told reporters after meeting his Belgian counterpart in Paris.