PARIS/BRUSSELS - 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.

The French Navy releases footage to BBC showing warplanes taking off to carry out strikes in the Syrian city of Raqqa, Islamic State's stronghold.

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 organise 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 US-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 mobilised a team in Belgium that benefited ... from help in France," French Interior Minister Bernard Cazeneuve told reporters after meeting his Belgian counterpart in Paris.

Stunned by the carnage, thousands of people thronged to makeshift memorials at four of the sites where the attacks took place, laying flowers and lighting candles to remember the dead.

"We are living a nightmare," said Caroline Pallut, whose 37-year-old cousin Maud Serrault died when gunmen attacked the Bataclan concert hall, killing at least 89 people -- the bloodiest single incident on Friday night.

"It is all so senseless. She had only just got married."

The death toll rose to 132, with three more people dying on Sunday from their wounds. Some 103 have been identified, including many young people and many foreigners, out relaxing on a Friday night in one of the world's most visited cities.

In a sign that at least one gunman might have escaped, a source close to the investigation said a Seat car believed to have been used by the attackers had been found in the eastern Paris suburb of Montreuil with three Kalashnikov rifles inside.