Prisoners seized at least 10 security guards as hostages during a riot in a Lebanese prison on Saturday, a police source said.
Riots break out frequently in Lebanon's overcrowded Roumieh Prison, built for 1,500 inmates but housing more than 3,000. Many say they are political prisoners and should be released.
"The prisoners on the second floor are burning mattresses and are holding about 10 guards hostage," the source said, requesting anonymity as he was not authorised to speak to media.
He said prisoners had timed the riot to coincide with Pope Benedict's three-day visit to Beirut to draw attention to their demands.
"These types of problems happen often; it's not a big deal. But they know the timing for a riot is good," he said.
Security sources said they were negotiating with the inmates and believed the guards would be freed soon.