Egypt: Protesters raid on Cairo state security HQ
Egyptian protesters have stormed the headquarters of the secret police in Cairo, demanding that the organisation be dismantled.
It followed rumours that officials were destroying documents that could be used in court to prove human rights abuses.
On Friday, some 200 protesters stormed the agency's offices in Alexandria after police fired on protesters.
The abolition of the force has been a demand of protesters who ousted Hosni Mubarak as president in February.
Egypt's State Security Investigations - which is reported to have some 100,000 employees and a large network of informants - is widely accused of human rights abuses, including torture of detainees.
In Cairo, hundreds of demonstrators gathered outside the national headquarters of the state security forces in Sixth of October city, on the edge of the capital.
One of the protesters told the BBC they had been allowed into the building by guards and had discovered piles of shredded documents, but nobody inside.
The army has secured the building.
The internal security services were the feared enforcers of Hosni Mubarak's three decades in power, says the BBC's Alastair Leithead in Cairo.
It was their agents that used violence to try and stop the protests in Tahrir Square - and they have now become the latest target of continuing if small scale protests, our correspondent says.
On Saturday, former Interior Minister Gen Habib al-Adly - who had been in charge of the secret services - appeared in court accused of money-laundering and corruption. He denied all the charges.
On Friday, the country's newly appointed Prime Minister Essam Sharaf vowed to reform the dreaded security apparatus.
Addressing thousands in the capital's Tahrir Square, the focal point of protests that toppled Mubarak, he said he hoped Egypt's "security apparatus will serve the citizens".
In the port city of Alexandria later, several people were injured as protesters and police clashed in the lower floors of the state security agency there.
Soldiers eventually regained control of the building where witnesses said officers had been trying to destroy papers.
Mr Mubarak stepped down after 18 days of protests, handing over power to the armed forces.