Fierce fighting between sectarian groups in the northern Lebanese city of Tripoli has left six people dead and at least 33 others wounded.

Lebanese officials say most of the wounded in Friday's fighting were caught in the crossfire, as Sunni and Shi'ite gunmen exchanged rocket-propelled grenades and machine gun fire.

They say most of the fighting has been concentrated in the Sunni Bab el-Tabaneh district and the Alawite (a Shi'ite sect) neighborhood of Jabal Mohsen.  Witnesses say some residents have been trying to flee their homes.

Ongoing clashes in Tripoli have killed at least 17 people since June.

Lebanon formed a unity government two weeks ago, after months of fighting between the Western-backed government and the Hezbollah-backed opposition threatened to descend into civil war.

Prime Minister Fuad Siniora has said one of the government's most important tasks will be to restore confidence in the political system.

Under the terms of a Qatari-brokered deal signed in May, the Hezbollah-backed opposition has veto power with its 11 seats in Lebanon's 30-member cabinet.

Some information for this report was provided by AFP, AP and Reuters.