Residents say Islamic State has beheaded and stoned to death many people in areas it controls in Syria.
An IS Twitter account published two photos of a smiling man who it said carried out the suicide operation.
One photo showed a blindfolded man kneeling with his head on a wooden block as a masked man in black raised a sword over his neck.
Israel has carried out several airstrikes in Syria that have targeted sophisticated weapons systems.
After three years of fighting in Syria, more than 3.2 million refugees are registered in neighbouring countries.
The base has been used by the government in the past months to launch air raids on areas held by the IS.
The Islamic State group already controls the surrounding province.
The attack which killed atleast 15 and wounded 5, took place in al-Walid on Iraq’s side of the border.
The coalition aistrikes took place overnight and targeted IS positions in the city of Raqqa as well as the Division 17 air base.
Dhar was arrested in September in the UK along with eight others on suspicion of encouraging terrorist offences.
Some of the airstrikes Tuesday struck a popular market near a museum and an industrial neighborhood in the city along the Euphrates River.
With its influence in the Middle East weakened, Moscow is trying to restart Syria talks that collapsed earlier.
Biden announced $135 million in new U.S. aid for Syrian civilians, including some for Turkey.
Nine civilians, including a woman, were killed in a Syrian government air raid on Wednesday on the city of Raqa.
A US-led coalition is carrying out air strikes against IS jihadists in both Iraq and Syria.