Dozens of people have been killed in fierce fighting between Lebanese troops and a radical Islamic group around the city of Tripoli, in northern Lebanon.

After a morning raid against a building used by the militants, the group - Fatah al-Islam - attacked Lebanese troops near a Palestinian refugee camp.

At least 13 Lebanese soldiers were wounded in the attack.

The attack by Fatah al-Islam, a Palestinian splinter group alleged to have links to al-Qaeda, led to a response by the military.

Troops gathered in Tripoli for an assault on a building used as a base by Fatah al-Islam fighters.

The troops then stormed into the buildings, exchanging fire with the militants but taking significant casualties as well.

Some suspected fighters were arrested but the continuing fighting was among the worst civil violence in Lebanon in recent years.

The fighting brought curious civilians out onto the streets to watch as the battle unfolded around them.