French President François Hollande declared the ISIS-linked attack in Paris “an act of war”, on Saturday. France has now responded by launching ferocious retaliatory airstrikes against ISIS targets in Raqqa, Syria on Sunday.

“The French Ministry of Defense said it targeted a command post and a terrorist training camp, dropping 20 bombs on ISIS’s de facto capital in Raqqah, Syria,” according to ABC News. “The first target included a command post, jihadist recruiting centre and a weapons warehouse, the ministry said.”

Speaking on the sidelines of the G20 summit in Turkey, French Foreign Minister L. Fabius said France has always said it would react in “self-defense”.

‘That’s what we did today with the strikes on Raqqa. We can’t let Daesh attack without a reaction,” Fabius said, not naming Islamic State.

France’s retaliation came in simultaneously as Obama held talks with allied leaders and with Russian President Putin, at the summit being held in Antalya.

The French statement said the operation, launched from bases in the United Arab Emirates and Jordan, was conducted in coordination with the U.S. military command, which has compiled an extensive target list in Raqqa. U.S. officials, speaking at the G20 summit that President Obama is attending, said the French operation was discussed between the two militaries, as well as in telephone calls Saturday and Sunday between Defense Secretary Ashton Carter and his French counterpart.

According to Business Insider, foreign minister of Iraq Ibrahim al-Jaafari said Iraqi intelligence had obtained information before the Paris attacks that the Islamic State was planning an imminent terrorist attack overseas that may have been targeting “in particular” France, the United States and Iran.

“We notified these countries and warned them,” Jaafari said in the statement.

The highly coordinated attacks on several important locations in Paris on Friday evening have shaken the gathering of global leaders. The Islamic State claimed responsibility for the attacks. Intelligence officials said three teams of terrorists affiliated with the extremist group carried out the operation.

“We support the French authorities in their determination to deal with the terrorist threat,” a NATO official said Sunday, “and a number of allies are already working with France on their ongoing operations and investigations in the wake of the attacks.”