A suspected car bomb damaged a top security compound in central Cairo on Friday (January 24), killing at least four people in one of the most high-profile attacks on the state in months, security and medical sources said.

The explosion damaged the face of the Cairo Security Directorate, which includes police and state security, and sent smoke rising over the capital, raising concerns that an Islamist insurgency is gathering pace.

The dead included three policemen. State television quoted the Cairo governor as saying 50 people were wounded.

State television quoted witnesses as saying gunmen on motorcycles opened fire on buildings after the explosion.

There was no immediate claim of responsibility for the attack, which came a day before the third anniversary of the uprising that toppled autocrat Hosni Mubarak and raised hopes of a stable democracy in the Arab world's biggest nation.

Instead, relentless political turmoil and street violence have hit investment and tourism hard.

Attacks in other parts of Egypt have been rising. The assault on police headquarters will likely encourage the state to crack down harder on the Brotherhood, which it accuses of carrying out terrorist acts. The Brotherhood says it is a peaceful movement.

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