Updated

A U.S. organization that monitors militant activity online says the leader of the Islamic State group has released a new message encouraging his followers to keep up the fight for the IS-held city of Mosul in Iraq.

The SITE Intelligence Group says the speech purporting to be from Abu Bakr al-Baghdadi was released in an audio recording, more than a half hour long, late on Wednesday.

In the recording, al-Baghdadi, rallies fighters especially in Mosul, calling on them to obey orders while remaining resilient and steadfast. He urged others to carry out attacks in Saudi Arabia and Turkey.

The Islamic State group is fighting to hold Iraq's second city of Mosul as Iraq forces and allied Kurdish forces advance on the city with U.S.-led coalition support.