An Isis spokesman and possible successor to its dead leader has also been killed, Syrian Kurdish forces have said.

They claimed Abu Hassan al-Muhajir died in a joint operation with US troops in northern Syria.

US special forces had killed the extremist group’s leader Abu Bakr al-Baghdadi​ just hours before.

Mazloum Abdi, the commander of the Kurdish-led Syrian Democratic Forces, said his group’s intelligence co-operated with the US military to target Muhajir, who was a key aide to Baghdadi, in a village near Jarablus, a town in northwestern Syria.

If confirmed, the death would be another blow to Isis.

The British-based Syrian Observatory for Human Rights also reported Muhajir’s death, saying he was travelling in a convoy made up of an oil tanker and a car.

The US raid that killed Baghdadi, the shadowy Isis leader who presided over its global jihad and became arguably the world’s most wanted terrorist, took place just before midnight on Saturday in Syria’s Idlib province.

It was a milestone in the fight against Isis, which brutalised much of Syria and Iraq and sought to direct a global campaign from a self-declared “caliphate”.

A years-long campaign by American and allied forces led to the recapture of the group’s territorial holdings, but its violent ideology has continued to inspire attacks.

Syrian Kurdish forces spokesman Mustafa Bali said his fighters believe Muhajir was in Jarablus to facilitate Baghdadi's travels to the area, which is administered by Turkey-backed fighters.

"More (Isis figures) remain hiding in the area," Mr Bali said late on Sunday.

Little is known about Muhajir, who assumed the role of a spokesman after his predecessor was killed in an air strike in 2016. He was believed to be a possible successor to Baghdadi.

Baghdadi’s identity was confirmed by a DNA test conducted onsite, US president Donald Trump said.

The operation coincided with a low point in Mr Trump’s presidency as he is mired in impeachment proceedings.

The president is also facing widespread Republican condemnation for his Syria policy.