BEIRUT: Clashes broke out between anti-government demonstrators and supporters of the Shi'ite groups Hezbollah and Amal in the Lebanese capital, Beirut, early on Monday, as tensions escalated when demonstrators blocked a main bridge.

Lebanon has faced five weeks of anti-government protests, fuelled by anger at corruption among the sectarian politicians who have governed Lebanon for decades. Demonstrators want to see the entire ruling class gone from power.

Hezbollah and Amal were both represented in the coalition government led by Prime Minister Saad al-Hariri, who quit on Oct. 29 after the protests began. The heavily armed Hezbollah, which is backed by Iran, had opposed Hariri's resignation.

Army soldiers and riot police formed a barrier separating the protesters from the supporters of the Shi'ite groups on a main road known as the Ring Bridge as rocks were thrown by both sides, television footage broadcast by Lebanese media showed.

Security forces fired tear gas to disperse the crowds, three local television stations reported.

Supporters of Hezbollah and Amal waved the groups' flags. Earlier, they had chanted: "Shia, Shia" and slogans in support of Hezbollah leader Sayyed Hassan Nasrallah. On the other side, demonstrators chanted: "Revolution, revolution".

Lebanese broadcaster al-Jadeed reported that fighting apparently broke out when Hezbollah and Amal supporters blamed other demonstrators for making offensive comments about Nasrallah. Reuters could not independently verify the report.

The ground was strewn with rocks. A motorcycle was set on fire.

The Lebanese civil defense said on its Twitter account that it was administering first aid to five people suffering from "various injuries."

It was the worst tension in Beirut since a mob loyal to Hezbollah and Amal attacked and destroyed the main protest camp in central Beirut last month. The protests have been overwhelmingly peaceful.