A man purported to be the reclusive leader of the militant Islamic State Abu Bakr al-Baghdadi making what would have been his first public appearance, at a mosque in the centre of Iraq's second city, Mosul, according to a video recording posted on the Internet on July 5, 2014, in this still image taken from video. REUTERS/Social Media Website via Reuters TV/File Photo

WASHINGTON (Reuters) - The United States on Friday more than doubled its previous reward for information on Islamic State leader Abu Bakr al-Baghdadi, offering $25 million for information that would help locate, arrest or convict the head of the jihadist group.

The U.S. State Department’s Rewards for Justice program previously offered $10 million for information on Baghdadi, announced in October 2011. The increase was announced in a statement on Friday.

Baghdadi, an Iraqi whose real name is Ibrahim al-Samarrai, declared himself the caliph of a huge swath of Iraq and Syria two years ago.

His exact location is not clear. Reports have said he may be in the Islamic State-held city of Mosul, Iraq, or in Islamic State-held territory to the west of the city, close to the border with Syria.

Kurdish officials believe that growing pressure resulting from a coalition military assault on Mosul is causing Baghdadi and his top lieutenants to move around and try to hide themselves.