Russia and France on Tuesday carried out a number of air strikes on Raqqa, the Islamic State, ISIL, stronghold in Syria, as other countries plan to join the fight, Le Mond and Reuters have reported.

The Russian strikes, described as significant, were conducted with cruise missiles from ships in the Mediterranean Sea with the United States notified as part of an agreement on air safety between the two countries.

Earlier on Tuesday, France said it targeted Raqqa, with its Rafale and Mirage 2000 fighters dropping at least 16 bombs, four days after the deadly Paris suicide attacks that left 129 people dead.

“For the second time in 24 hours the French military conducted an air raid against Daesh [derogatory name for Islamic State] in Raqa [Raqqa] in Syria,” a statement from the French ministry read.

“Both targets [chosen for the attack] were hit and destroyed simultaneously…Conducted in coordination with US forces, the raid was aimed at sites identified during reconnaissance missions previously carried out by France,” the statement further said.

France has also appealed to European Union members for military assistance in its operations in the Middle East and Africa.

“France cannot do everything, in the Sahel, in the Central African Republic, in the Levant and then secure its national territory,” French Defense Minister, Jean-Yves Le Drian, said on Tuesday.

In another development, Russia’s Defence Minister, Sergey Shoigu, has announced that the country will double its attack on ISIS in Syria, including the deployment of 25 long-range bombers. This means Moscow will be launching some of these attacks from within its own territory.

Prime Minister David Cameron has also promised the involvement on Britain in the fight against ISIS, telling the House of Commons that the country cannot afford to “stand neutral” because some of the foiled attacks against the country were planned in Raqqa.

“We must step up joint effort to deal with ISIS,” Cameron said, adding that 1, 900 spies will be recruited in this regard.