Riots have erupted in Lebanon's biggest prison after inmates took seven security officers hostage.
Smoke could be seen coming from one part of the jail in Roumiyeh, northeast of Beirut on Thursday. Early reports suggest inmates set fire to some of their belongings.
Officials said negotiations were being held to try to secure the release of the wardens before resorting to force, although they would not release the hostagetakers' demands.
They said the rioters included Palestinian as well as Lebanese prisoners.
The jail is made up of several buildings and is known to hold four senior security officials accused of having a role in the assassination of Rafiq al-Hariri, the former Lebanese prime minister, as well as members of the armed group Fatah al-Islam.
However, the officials said neither the detained officers nor the Fatah al-Islam members were near where Thursday's riots were taking place.