Senior Isis commander Abu Sayyaf killed by US special forces during overnight raid on house in Syria

The Pentagon said commandos freed a Yazidi woman kept as a sex slave

Secretary of Defense Ash Carter hailed the raid as a triumph (Getty Images)

US special forces have killed a senior Isis leader named as Abu Sayyaf in an operation aiming to capture him and his wife in Syria.

Ash Carter, the Secretary for Defence, said commanders entered his home in al-Amr on Friday night on the previously secret mission.

Sayyaf and his wife, Umm Sayyaf, were believed to be involved in Isis’ military operations as well as its control of oil fields, gas supplies and finance.

Isis has been advancing towards its latest target of Palmyra in Syria (EPA)

Mr Carter said the man was shot dead in a gun battle after “engaging” American troops, who captured his wife.

A young Yazidi woman, believed to be one of many kept as sex slaves by Isis militants, was freed during the operation.

The Pentagon claimed that Mr Sayyaf’s wife was a suspected member of the so-called Islamic State and “played an important role” in its activities.

Hailing the operation as a triumph, Mr Carter said no US troops were killed or injured.

Isis is leading an international coalition mounting air strikes against Isis in Syria (Getty Images)

He added: “The operation represents another significant blow to Isil (Isis) and it is a reminder that the United States will never waver in denying safe haven to terrorists who threaten our citizens, and those of our friends and allies.

“I thank the extraordinary men and women in uniform who executed this complex and challenging mission, along with all those who supported it.

“Their professionalism, dedication, and valour are a deep source of pride and inspiration to us all.”

The US is leading separate international coalitions mounting air strikes against Isis and other extremist insurgents in Iraq and Syria.

Security forces in both countries are struggling to hold back Islamists making continued gains, including seizing much of the Iraqi city of Ramadi on Friday.

Syrian state media earlier reported that government troops killed at least 40 Isis fighters, including a senior commander in charge of oil fields, in an attack on Saturday.

The dead commander was named as Abu al-Teem al-Saudi.

Abu Sayyaf is also the name of a militant Islamist group based in the Philippines, which swore an oath of allegiance to Isis in July last year.

Additional reporting by AP