The United States has said a senior Al-Qaeda leader has been killed in a US drone strike in Syria.

The Pentagon said Abdul Hamid al-Matar died in the airstrike in the northwest of the country.

He was targeted two days after an attack on a base in southern Syria used by the US-led coalition fighting the so-called Islamic State group.

Central Command spokesman Army Major John Rigsbee said in a statement that there were no known casualties from the strike, adding that it was conducted using an MQ-9 aircraft.

He said: "The removal of this Al-Qaeda senior leader will disrupt the terrorist organisation's ability to further plot and carry out global attacks."

At the end of September the Pentagon killed Salim Abu-Ahmad, another senior Al-Qaeda commander in Syria, in an airstrike near Idlib in the country's northwest.

He had been responsible for "planning, funding, and approving trans-regional Al-Qaeda attacks," according to Centcom.

Major Rigsbee said: "Al-Qaeda continues to present a threat to America and our allies. Al-Qaeda uses Syria as a safe haven to rebuild, coordinate with external affiliates, and plan external operations."

The ongoing war in Syria has created a complex battlefield involving foreign armies, militias and jihadists.

The war has killed around half a million people since starting in 2011 with a brutal crackdown on anti-government protests.