By Mark Lowen
BBC News, Belgrade
A notorious criminal in Bosnia, deemed a national security threat, has gone on the run from prison in the central town of Zenica.
The man, Karray Kamel bin Ali, also known as Abu Hamza, was serving a four-year sentence for armed robbery and domestic violence.
Bin Ali, who was born in Tunisia, was previously suspected of plotting attacks in Italy.
He came to Bosnia during the Balkan wars of the early 1990s.
Bin Ali was over half-way through his recent sentence.
The authorities at the high security prison in Zenica, in central Bosnia, granted him leave for good behaviour, allowing him to visit his family.
The prison authorities said this was normal practice.
He had been due to return to the prison on Monday but failed to do so. An arrest warrant has been issued for him.
Prior to his current sentence, he was imprisoned in 2000 for murder, having been arrested in Germany after three years on the run.
When he came Bosnia in the early 1990s, he fought with the al-Mujahideen unit against the Serbs and Croats.
He was granted Bosnian citizenship after marrying a local woman, and became integrated within the theologically conservative Wahhabi Muslim community.
The police in Zenica told the BBC they had warned the Bosnian justice ministry on Thursday that Bin Ali was likely to flee if his leave was granted.
That is disputed by the ministry, which maintains it only received the message on Monday - the day he was scheduled to return.
An internal inquiry is now under way.