BEIRUT (Reuters) - Lebanese security forces on Saturday fired water cannons and tear gas at anti-government protesters trying to breach a security barricade outside government headquarters in central Beirut.

Some protesters managed to open a metal gate blocking the path to the area but were pushed back.

"Rioting and attacks against Internal Security Forces have begun, we therefore ask peaceful protesters to leave Riad al-Solh area for their safety," the ISF said on Twitter.

A planned march on Saturday under the slogan "We won't pay the price" began peacefully but then saw a repeat of violence that has marked recent protests against a political class that demonstrators say has plunged the country into its worst crisis in decades.