Egypt violence: Cairo clashes go into fourth day (Video).

At least one person has died in fresh clashes between protesters and troops in the Egyptian capital Cairo, bringing the death toll since Friday to 12, BBC News reported. 

Security forces moved into Tahrir Square before dawn, using batons and tear gas to drive out the protesters, who retaliated by throwing stones.

The ruling military said the clashes were a plot to destabilise the country.

US Secretary of State Hillary Clinton said she was "deeply concerned" by the violence.

She urged security forces "to respect and protect the universal rights of all Egyptians, including the rights to peaceful free expression and assembly".

"Those who are protesting should do so peacefully and refrain from acts of violence," Clinton added.

UN Secretary General Ban Ki-moon said he was highly alarmed at the "excessive use of force employed by the security forces", and called for the authorities to act with restraint and uphold human rights. 

In recent weeks, thousands have taken to the streets, demanding the ruling military council hand over power to a civilian government. 

The council assumed presidential powers after Hosni Mubarak stepped down in February in the wake of a popular uprising. It has pledged to hand power to an elected president by July.

The protesters fled down nearby streets away from the cabinet office and parliament building, where they have been throwing stones and petrol bombs at security forces. 

"Rocks and Molotov cocktails are being thrown on both sides," one witness, Ahmed Raafat, told the BBC. "Water canons are used against protesters, and from time to time we hear gunshots coming from the security forces' side."

Assistant Health Minister Adel Adawi said one person had been killed on Monday.

Adawi added that 201 people had been injured on Sunday alone, with 136 needing treatment in hospital. Most of those admitted were suffering from bruises, cuts, burns and concussion, he added.