New attacks 'being prepared' against France, Europe

French Prime Minister Manuel Valls said on Monday that authorities believe new terror attacks are being planned in France and in other European countries following the carnage in Paris.

"We know that operations were being prepared and are still being prepared, not only against France but other European countries too," he said.

French police carried out dozens of pre-dawn raids on suspected "radicals" on Monday, focussing particularly on the Lyon area where they made five arrests and seized "an arsenal" of weapons, police sources said.

Thirteen raids were carried out around the southeastern French city, leading to five arrests and the seizure of a rocket launcher, a Kalashnikov assault rifle, bulletproof vests and handguns, local police said.

France prepared to fall silent at noon Monday to mourn victims of the Paris attacks after its warplanes pounded the Syrian stronghold of Islamic State, the militant group that has claimed responsibility for the slaughter.

With a manhunt under way for suspects across Europe, French police released a photograph of a "dangerous" suspect also wanted in Belgium, where Friday's bloodbath may have been planned.

France was to observe a minute's silence at midday (1100 GMT), which the European Union has called on all member states to respect. In the United States, the Stars and Stripes will fly at half-mast at the White House until sunset Thursday.

President Francois Hollande will observe the silence at the Sorbonne University, in recognition of the large toll of young people among the 129 dead. Another 352 were injured, scores of them seriously.

Despite a state of emergency, schools were to reopen Monday morning with museums, theatres and other cultural centres following at 1:00 pm after being shut in the wake of the attacks.

French warplanes pounded Islamic State's Syrian stronghold on Sunday in the nation's first retaliation against the militants.

The raid destroyed an IS command post, a recruitment centre, a munitions depot and a "terrorist" training camp in Raqa, the defence ministry said.

The operation was coordinated with US forces by a dozen aircraft which took off from Jordan and the United Arab Emirates, it said.

Hollande has denounced the Paris attacks as an "act of war" and vowed to hit back against IS "without mercy".

Apparent French air strikes overnight hit weapons depots and a training camp in the de facto Syrian capital of the Islamic State group, a monitor said on Monday.

"There were at least 36 explosions overnight in Raqa city, some caused by air strikes and some by weapons and explosives detonating after being hit," said Rami Abdel Rahman, director of the Syrian Observatory for Human Rights.

"The blasts shook the entire city. There were strikes on both the north and south of Raqa," he told AFP.

Abdel Rahman said the strikes were believed to have been carried out by French aircraft.

Among the targets hit was Brigade 17, a military encampment including weapons stores and a training facility.

The Britain-based monitor could not immediately confirm any casualties in the strikes, which come after IS claimed responsibility for attacks that killed at least 129 people in Paris.

"IS has imposed a security alert on the city, and it is difficult to confirm information about casualties from hospitals there," Abdel Rahman said.

Photo Caption :French Prime Minister Manuel Valls at the Elysee Presidential Palace in Paris on 15 November, 2015