Mubarak's thugs fire at protestors in Cairo

Supporters of Hosni Mubarak on Thursday fired at anti-government protesters in the Egyptian capital's Tahrir Square, killing at least six people, as violence escalated just a day before the opposition's proposed massive rally to oust the embattled president.

Still reeling from Wednesday's attack in which Mubarak's supporters charged into the square on horses and camels, the opposition protesters were fired upon from a bridge near the square, killing six people, including three on the spot.

The protesters refused to leave Tahrir Square, which has become a hub of the 'Down Mubarak' campaign. They were fired upon at 4 am on Thursday morning. An opposition spokesman claimed that the violence was being unleashed by paid thugs and plainclothes policemen to crush an unprecedented nine-day-old movement.

Witnesses reported that at least three bodies were being carried away in ambulances. Gunfire rained into the square from at least three directions, they said, adding that the military did not intervene. Pitched battles were also reported between pro and anti-Mubarak groups for the control of a high vantage overpass leading to the square.

The clashing groups also hurled rocks and bombs at each other. The fighting between the groups erupted 12 hours earlier as Mubarak's supporters charged with whips into the protesters, while others rained fire bombs and rocks from rooftops.

Soldiers ringing the square from all sides with tanks and armoured carriers fired occasionally in the air overnight but did not intervene otherwise.

The violence came after the beleaguered president went on air on Tuesday to say that he would not stand for re-election in September, but refused to quit immediately, triggering an ultimatum by the protesters. They have set Friday as a deadline for him to step down. Mubarak, 82, has been in power since 1981.

The unceasing violence has witnessed a sharp escalation of attacks on Western media personnel, which has come in for strong condemnation by United States Secretary of State Hillary Clinton and western governments.