French Prime Minister Manuel Valls urged Russia on Sunday to direct air strikes at Islamic State jihadists alone in Syria, as the West raises concerns Moscow will target moderate rebel groups opposed to Syria's president.

Speaking to journalists on a visit to Japan, Valls said Russia should not "get the wrong targets", echoing the words of French President Francois Hollande to Russian President Vladimir Putin at a Paris summit on Friday.

Traffic resumed through the Channel Tunnel connecting Britain and France early Saturday several hours after being suspended when 113 migrants entered the French side of the tunnel complex, the company operating it said.

Services had been suspended for just over seven hours throughout the night, but resumed early on Saturday with a Eurostar train from England entering the tunnel at 8:05am (0605 GMT), a Eurotunnel spokeswoman told AFP.

Russia carried out a third day of air strikes in Syria on Friday and said it had hit Islamic State's 'capital' as President Vladimir Putin faced mounting international criticism over his military campaign.

Moscow said it had bombed "an IS training camp" and a command post in the IS bastion f Raqa on Thursday, but on Friday it targeted rebel groups opposed to Syrian President Bashar Assad.

France demanded Wednesday that Russia confirm the targets of its air strikes in Syria, amid concerns they may not have been aimed at the Islamic State group, before accepting the enlarged coalition Moscow wants.

"Of course, we must fight together as hard as we can against Daesh," French Foreign Minister Laurent Fabius told reporters in New York, using the group's Arabic acronym.

Italian police cleared a camp of migrants and activists from the border of France and Italy on Wednesday, with the occupants moving to rocks on the shoreline to avoid arrest and refusing to move.

The camp of around 50 people at Ventimiglia -- the town which became a flashpoint at the start of Europe's migrant crisis earlier this year -- was cleared because its occupants were using electricity and water without paying for it, a police spokesman said.

France's first air strike on the Islamic State group in Syria killed at least 30 jihadists, including 12 child soldiers, a monitoring group said on Wednesday.

"The French air strike (on Sunday) on an IS training camp in eastern Syria killed at least 30 IS fighters including 12 from the 'Cubs of the Caliphate,'" said Rami Abdel Rahman of the Syrian Observatory for Human Rights.

France has launched an inquiry into Syrian President Bashar Assad's regime for alleged crimes against humanity, saying it was forced to act in the face of "systematic cruelty".

The announcement Wednesday came after world powers sparred at the United Nations over the embattled Syrian leader's fate.

French Foreign Minister Laurent Fabius accused Russia Tuesday of displaying bravado on the Syria crisis that had yet to be backed up with action against the Islamic State group.

"You have to look at who is doing what. The international community is striking Daesh. France is striking Daesh. The Russians, for the time being, are not at all," Fabius told a news conference in New York, using the Arabic acronym for IS.

Prime Minister Tammam Salam has announced that French President Francois Hollande decided to postpone his trip to Beirut to ensure its success.

Hollande delayed his visit “probably to November until the circumstances that guarantee the success of the trip are available,” Salam said in New York.

France on Monday gave cautious backing at the United Nations to a call from Russian President Vladimir Putin for a "broad coalition" to fight the Islamic State group in Syria.

Speaking to the U.N. General Assembly, French President Francois Hollande called such a coalition "possible, desirable, necessary" but said it would have to have "a clear basis, otherwise it would never come to light."