TRIPOLI, Lebanon - Lebanese tanks were out on the streets of Tripoli on Saturday to restore security after nine people were killed in a fresh bout of sectarian fighting in the northern port city.

Militants from the rival Sunni Muslim and Alawite communities battled with rocket-propelled grenades and automatic weapons through the night in the latest violence to rock the Mediterranean city.

An AFP correspondent said that around 60 army vehicles fanned across Tripoli and that the shooting had died down.

An army statement said the troops "will use force if necessary to protect civilians and their property and bar armed presence" on the streets.

A 10-year-old boy and two women were among those killed on Friday while 50 other people were wounded after two attempts to secure a ceasefire.

"The army is working for real calm in the north," an army official told AFP, but added: "Security requires political agreement."

Tripoli MP Mohammed Kabbara agreed.

"The government is responsible for keeping the peace... but we see that the officials have resigned their duties and turned their backs on Tripoli," he said in a statement carried by the state-run National News Agency.

Kabbara said the violence that has wracked his city should be addressed in "a special clause in government policy" being drafted by cabinet ministers to ensure a lasting ceasefire.

"Will the clashes break out again each time there is a political row in the capital?" he asked.

"What is the price they want Tripoli to pay in order to stop the bloodbath?" he added after a meeting of local political and religious leaders.

Lebanon has been hit by sporadic outbreaks of violence despite a power-sharing deal between rival political factions in May which led to the election of Michel Sleiman as president and the creation of a unity cabinet.

The latest unrest came after the new cabinet hit snags in deliberations aimed at drawing up a policy agenda ahead of a parliamentary vote of confidence which would enable the government to be officially installed.

"This is a political conflict between the Lebanese. Rather than go to the constitutional institutions they are reverting to the use of weapons," the army official said.

Tanks and armoured vehicles patrolled the streets in the mainly Sunni Bab al-Tebbaneh district and the neighbouring, largely Alawite, Jabal Mohsen -- both impoverished areas.

Many shops remained shuttered for the second consecutive day and streets were largely deserted as families who had fled the battle zones on Friday waited for a return to calm before going home, the AFP correspondent said.

Bab al-Tebbaeh resident Ali Darwish, 63, said he spent Friday night with his three children and 14 grandchildren in a classroom without electricity.

"We are anxiously awaiting the army to bring back calm and stability, so we can go home. The situation in the school is unbearable."

In Friday's violence a rocket-propelled grenade slammed into an apartment building near a vegetable market, setting it ablaze, while another one hit a mosque in Bab al-Tebbaneh.

Interior Minister Ziad Barud and the head of the internal security forces Ashraf Rifi visted Tripoli late on Friday to assess measures to restore calm.

Clashes between the two sides have killed a total of 23 people and wounded more than 100 since June.

Bab al-Tebbaneh is a stronghold of the anti-Syrian parliamentary majority while the inhabitants of Jabal Mohsen mainly support the Syrian-backed opposition led by Hezbollah.

Tensions between the two communities date back to Lebanon's 1975-1990 civil war. Alawites are an offshoot of Shiite Islam who revere Imam Ali, the cousin and son-in-law of the Prophet Mohammed.

The violence erupted after cabinet ministers decided on Thursday night to postpone talks on the issue of weapons held by Hezbollah, the powerful Shiite Muslim political opposition movement and militia.

Hezbollah's arsenal is a key bone of contention in Lebanon's fraught political negotiations. -AFP