United States Secretary of Defense Jim Mattis on Friday said he cannot confirm reports of Islamic State group’s chief Abu Bakr al-Baghdadi’s death, AFP reported. On July 11, the Syrian Observatory for Human Rights had said it had confirmed information that al-Baghdadi had been killed.

“If we knew, we would tell you – right now, I can’t confirm or deny it,” Mattis said. “Our approach is we assume he’s alive until it’s proven otherwise, and right now, I can’t prove it otherwise.”

On June 16, Russia’s Defence Ministry had said it was investigating whether one of its air strikes in Syria in May had killed al-Baghdadi. There were disputed reports on the matter – The New York Times had said that the Russian Defence Ministry had claimed al-Baghdadi had been killed, but other agencies said the matter was still being investigated.

The last public footage of al-Baghdadi was released in 2014.