Protests turned violent on Tuesday in Lebanon's Sunni bastion of Tripoli as frenzied demonstrators torched an Al-Jazeera van while protesting the likely 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.

An AFP photographers witnessed similar incidents in the capital Beirut, where media considered close to the Shiite militant Hezbollah and its allies were attacked by stone-throwing and baton-wielding demonstrators.

There were no immediate reports of injuries in the city, where there was a heavy security presence.

A security official told AFP shots were fired in the air in Beirut. Shots also rang out in Tripoli.

The demonstrators in Tripoli also attacked a building housing the offices of Sunni lawmaker Mohammed al-Safadi breaking windows, doors and throwing furniture from the second-floor balcony.

Safadi had been allied with outgoing premier Saad Hariri's Western-backed coalition but is now backing the Hezbollah-backed candidate for premiership.

The incidents came amid a "day of rage" by the country's Sunni community to protest the likely appointment of billionaire businessman Najib Mikati, who hails from Tripoli, to head the next government.

Hezbollah's opponents view Mikati's candidacy as a bid by Hezbollah to impose on the Sunni community their choice for the premiership.

According to Lebanon's power-sharing system, the country's prime minister must be a Sunni Muslim.