A brigade of the security forces repelled a massive anti-regime demonstration with thousands of protesters from approaching the Presidential Palace in Yemen's capital Sanaa on Sunday, beating them with electrical batons and rifle butts.

The protesters called for ousting President Ali Abdullah Saleh and expelling his family members from top military and security positions, including Saleh's eldest son Ahmed Ali who commands the special forces.

"People have one demand, ousting Saleh along with his family members in military," protesters shouted as they approaching the Presidential Palace, marching in long and crowded rows from Sanaa University.

Protesters also chanted other slogans such as "People want the regime to fall. After Mubarak, it's Saleh's turn."

Heavy security forces have been dispatched to the Hadda Street, about five km away from the Presidential Palace, storming into the protesters and beating them with stones, electrical batons and rifle butts, according to a Xinhua reporter.

Many people were injured and about 120 people, including a Xinhua cameraman were arrested by the police. The cameraman was detained for three hours before being released.

Meanwhile, around 2,000 government supporters gathered at Al-Tahrir square of Sanaa's downtown. The supporters blocked all streets leading to the square to prevent the protesters from gathering at the downtown, a member of the ruling party told Xinhua.

"We expected that the anti-regime march would head to Al-Tahrir, but unfortunately we were informed that the protest march headed towards the Presidential Palace," he said.

The huge demonstration in Sanaa took place simultaneously with another anti-regime march of about 5,000 protesters in southern Taiz province, according to eyewitnesses.

Meanwhile, the opposition leaders issued a statement on Sunday, declaring their acceptance to a political reform initiative offered by Saleh earlier this month saying he will step down in 2013 and not to pass power to his son.

Saleh, who has been in power for more than 30 years offered his concessions to the opposition on Feb. 2 following the spreading Arab unrest.

In its statement, the opposition coalition agreed to begin a national dialogue with Saleh's ruling party, but stipulated that Saleh must expel all his family members from top military and security posts, including his son Ahmed Ali, who was widely believed to be the next president of the poor country.

The opposition also said that security authorities had arrested more than 130 members of the opposition coalition during the previous demonstrations, calling on Saleh to release them.