Uniformed and plain-clothed Egyptian policemen drag a pro-reform protester as she is arrested near a courthouse in Cairo

Egyptian riot police have beaten and detained pro-democracy demonstrators marching toward a Cairo courthouse to support judges who face a disciplinary hearing for calling last year's parliamentary elections fraudulent.

A VOA correspondent on the scene says police - wearing helmets and armed with sticks - dragged protesters and reporters into police vans.

The correspondent saw police beat an Al-Jazeera cameraman and confiscate his tapes.

The number of arrests is unclear.

Security forces, in the thousands, cordoned off streets leading to the courthouse to prevent the marchers from getting near the building.

The two judges refused to attend the disciplinary hearing which took place without them. It will resume next Thursday.

The judges are accused of harming the reputation of the judiciary for alleging that last year's election results were tainted.

During a hearing last month, riot police also beat back demonstrators.

Since then, security forces have detained at least 40 pro-reform activists. The government of President Hosni Mubarak has also targeted the banned - but tolerated - Muslim Brotherhood, the largest opposition group in parliament. Recently, police have detained scores of Muslim Brothers.

Emergency laws in Egypt allow the government to make arrests and hold detainees for long periods without filing charges.

Elsewhere in Cairo, at least five riot policemen died and 20 were injured when their van drove off a bridge. The police were being deployed to the courthouse, where riot police were beating demonstrators and trying to disperse them.