Lebanese soldiers take positions in a street during clashes with protesters in Beirut's suburbs January 27, 2008. [Photo: Reuters]

Related: Gunfight Breaks Out bet. Army, Demonstrators in S. Beirut

The death toll rose to seven in riots which broke out between the Lebanese army and the demonstrators in southern suburb of Beirut on Sunday.

"Seven demonstrators were killed in the protest," which was staged by Lebanese opposition parties over frequent power cuts, an anonymous source from the opposition party Hezbollah told Xinhua.

An earlier report said three protestors were killed, which included two members from the opposition movement Amal and a third member from Hezbollah. Over 20 others were also injured in the riots.

Hamza, 35, was shot dead as he was working with the coordination committee between the demonstrators and the Lebanese army. His death raised more violence and expanded to the airport road and Mar Elias area where demonstrators also blocked roads by burning tiers.

"At 16:00 local time, some protestors tried to block the road of Mar Mikhail, the army immediately intervened to disperse the protest," the Army command said earlier in a statement.

"But unidentified fire hit the protestors killing at least two of them and wounding 19 others," the statement said, adding that the army will immediately open an investigation to find out the source of fire.

The clashes broke out when the army tried to stop some protestors blocking traffic with burning tires in Mar Mikhail - Al Cheyah in the southern suburb of Beirut.

At around 4:00 p.m. (1400 GMT), some 50 demonstrators started burning tiers closing the road linking Mar Michael to Al Cheyah in protest against power cuts, chanting slogans against the government of Premier Fouad Seniora, local LBC TV reported.

Lebanon is currently facing the most serious political deadlock since the end of the 1975-1990 civil war. For the first time in its history, the presidential seat has been vacant since Nov. 24 of 2007 when former President Emile Lahoud stepped down.

A long-awaited parliamentary session to elect president has been postponed for a 13th time, from Jan. 21 to Feb. 11.

The presidency deadlock deepened the Lebanese political crisis as fears are mounting that failure in reaching a deal on the presidential candidate could result in more violence in the country.