Washington, Feb 12 (IANS): Islamic State (IS) leader Abu Bakr al-Baghdadi was injured in an airstrike in May 2017 and had to relinquish control of the terror group for up to five months, US officials told CNN.

US intelligence agencies have assessed with a high degree of confidence that the world's most wanted man was near Raqqa, Syria, when the missile struck, the officials said late Sunday.

Their assessment is based on reports from IS detainees and refugees in northern Syria that emerged months after the airstrike.

Baghdadi's injuries were not considered life-threatening but they did mean he could not continue to command the daily operations of the group, said the officials.

However, it remains unclear whether Baghdadi was hit in a targeted attack or if he was part of "collateral damage".

The other factors that remain unclear are who fired the missile, the exact date of the strike or whether Baghdadi's injury was the result of a Russian missile.

"There have been isolated strikes by Russians in Raqqa, but as there's no timeline to it, we don't know if it's ours," a US official told CNN.

Baghdadi has made only one public appearance in July 2014 at the al-Nuri Mosque in Mosul, which was retaken by Iraqi security forces in June 2017.

IS has since released various audio messages it claims to be of Baghdadi.