Conversation so far:
What is Ibn al-Khattab's connection to Central Asia?
At the age of 18, Khattab left Saudi Arabia to participate in the fight against the Soviet Union during the Soviet invasion of Afghanistan.
What else did Ibn al-Khattab do, besides leave to fight in Afghanistan?
Ibn al-Khattab permanently incapacitated his right hand after an accident with improvised explosives.
What happened to Ibn al-Khattab after injuring his hand?
Ibn al-Khattab publicly admitted that he spent the period between 1989 and 1994 in Afghanistan and that he had met Osama Bin Laden.

Question: When did he enter the Balkans?
Self-contained rewrite: When did Ibn al-Khattab enter the Balkans?