The death of a senior ISIS leader has been confirmed by a news agency linked to the militant group.

Omar Shishani died in March after injuries sustained in an American air strike, according to the US. The jihadist figure was said to be close to the group's chief, Abu Bakr al-Baghdadi.

The Amaq news agency had originally denied the Pentagon's claim Shishani had been killed. It has now confirmed his death although its account conflicts with that of the US.

Amaq said he died in combat, fighting against forces trying to take the ISIS-held town of Mosul in Iraq. But the US said he died after an air strike in north-eastern Syria. Their account said Shishani had been sent to the town of Shaddadi to support local ISIS forces and that he died there, not in Iraq.

A statement on the Amaq website read: "Shaykh Umar ash-Shishani martyred in Shirqat as he participated in clashes to repel the campaign against the city of Mosul." 

His death came after the US offered $5m (£3.5m) as a reward for Shishani.

Shishani's real name was Tarkhan Batirashvili and he was also known as Omar the Chechen, according to the BBC.