At least two people have been killed and 25 injured in the Libyan capital, Tripoli, after militiamen opened fire on demonstrators.

The protesters had marched to the headquarters of the Misrata militia to demand that it leave Tripoli.

The militia were involved in last week's clashes in the capital, which also left two people dead.

The Libyan government has been struggling to contain numerous militias who control many parts of the country.

This is a serious development in the capital that is reminiscent of events in Libya's second city, Benghazi, earlier this year when anti-militia protesters attacked bases and more than a dozen people were killed.

Unlike last week, where the fighting was between two rival militias, the implications of any armed group facing off with civilians are potentially dangerous in the country because the majority of civilians still have weapons at home.

There have been increasing demands from civilians that the militias - which emerged during the 2011 revolution - disband or join the army, in line with an end-of-year deadline set by the interim government in Tripoli.

Two years after the overthrow of Col Muammar Gaddafi, Libya still has no constitution and divisions between secular and Islamist forces have paralysed parliament.