At least 37 people have been killed in a day of fighting between Lebanese troops and gunmen from a Palestinian refugee camp in northern Lebanon.

Some 14 fighters from the radical Fatah Islam group and 22 Lebanese soldiers died in intense battles, reports said.

Fatah Islam, said to be linked to al-Qaeda, killed some 15 soldiers in clashes around the Nahr el-Bared camp.

Soldiers then bombarded militants in the camp and fought battles at a house in Tripoli used as a base by fighters.

One civilian was reported killed and 40 civilians were injured, AFP news agency reported. A Lebanese army spokesman said another 27 soldiers were injured.

Lebanon is home to more than 350,000 Palestinian refugees, many of whom fled their homes when Israel was created in 1948.

'Unprovoked aggression'

Fighting erupted on Sunday morning after security forces raided a building in Tripoli to arrest suspects in a bank robbery.

After resisting arrest, militants said to belong to Fatah Islam then attacked army posts at the entrances to the Nahr el-Bared refugee camp, which is home to some 30,000 displaced Palestinians.

The military is banned from entering the camp under a 38-year-old deal.

Several hours later a large force of Lebanese troops hit back at Fatah Islam, storming the building on the outskirts of Tripoli and killing a number of militants.

Fatah Islam spokesmen portrayed the fighting as an unprovoked aggression by the Lebanese army.

"The problem began with repeated arrests of our brothers in Tripoli. We've always defended Sunnis in Lebanon," a spokesman called Abu Salim told al-Jazeera TV.

Hariri link?

Fatah Islam is a radical Palestinian splinter group alleged to have links with al-Qaeda. Lebanese officials also believe it has ties to Syrian intelligence.

Other Palestinian groups have distanced themselves from Fatah Islam, which emerged last year after splitting from a Syrian-backed Palestinian splinter group, says the BBC's Beirut correspondent Jim Muir.

After the violence broke out, Syria temporarily closed two border crossings with northern Lebanon because of security concerns.

Some link the eruption in violence to moves at the UN Security Council to set up an international tribunal to try suspects in the assassination of the former Prime Minister, Rafik Hariri, two years ago, our correspondent says.

Syria is against the tribunal, and some Lebanese government sources have accused Damascus of trying to stir up trouble to head it off.

Lebanon's Prime Minister, Fouad Siniora, said Fatah Islam was making a deliberate attempt to destabilize the country.

The Nahr el-Bared camp has been under scrutiny since two bus bombings in a Christian area of Beirut in February, blamed on Fatah Islam militants based in the camp.

Photo caption

Lebanese soldiers