The US has carried out precision air strikes against Isis targets in Syria amid concerns that the terror group will regroup in the “vacuum” created by the fall of Bashar al-Assad.

Joe Biden, the US president, said on Sunday afternoon it had struck targets after learning that Damascus had been overtaken by rebel groups. The US military will continue to operate in the region to quell the threat of IS.

“We’re clear-eyed about the fact that Isis will try to take advantage of any vacuum to re-establish its capabilities to create a safe haven,” said Mr Biden. “We will not let that happen. In fact, just today, US forces conducted a dozen precision strikes, air strikes within Syria, targeting Isis camps and Isis operatives.”

The president added that he would send members of his administration to Syria and work with Jordan, Lebanon, Iraq and Israel “should any threat arise from Syria during this period of transition”. He called the fall of Assad a “fundamental act of justice”.

The strikes were conducted by B-52 bombers, F-15 fighter jets and A-10 aircraft and hit Isis leaders, operatives and camps, CNN reported.

The US is also concerned about the Syrain rebels’ plan for a new government, given the “grim record of terrorism and human right abuses” among some of the groups in the rebel coalition, he said.