The leader of jihadist militant group Isis has called on Muslims to travel to Iraq and Syria to help build an Islamic state, in an audio message.
Abu Bakr al-Baghdadi called on Muslims to immigrate to the "Islamic State", saying it was a duty.
He made a "special call" for judges, doctors, engineers and people with military and administrative expertise.
Isis says it is forming an Islamic state, or caliphate, on the territories it controls in Iraq and Syria.
In an earlier audio recording this week, the Islamic State in Iraq and the Levant (Isis) proclaimed Abu Bakr al-Baghdadi as caliph and "leader for Muslims everywhere".
The central government in Baghdad has lost control of vast swathes of territory to Sunni militants, led by Isis, over the past month.
The group says its Islamic state will extend from Aleppo in northern Syria to Diyala province in eastern Iraq.
Setting up a state governed under strict Islamic law has long been a goal of many jihadists.