Protests turned violent on Tuesday in Lebanon's Sunni bastion of Tripoli as frenzied demonstrators wrecked an Al-Jazeera van while protesting the appointment of a Hezbollah-backed premier.

Angry demonstrators set upon the vehicle, smashing the windshield and tearing down the satellite dish before setting it on fire, AFP reporters witnessed.

Demonstrators also torched the mopeds of other media outlets considered close to the Iranian-backed Shiite group Hezbollah.

Local television reported similar incidents in the capital Beirut but security officials could not confirm the reports.

The incidents came as Sunni supporters of outgoing prime minister Saad Hariri held a "day of rage" to protest the likely appointment of Hezbollah-backed Sunni tycoon Najib Mikati to head the next government.