Three bombs explode in Cairo, one at a Metro station, and two bombs outside police headquarters A blast in central Cairo kills four people and injures dozens, witnesses say gunfire was heard. A car bomb has struck the police headquarters in Cairo, killing at least one person in the blast. IN a matter of minutes, a third bomb has gone off in Cairo near police headquarters after a car bomb and metro station bomb exploded. The third bomb comes after the second bomb near a metro station wounded five police, hours after a car bomb struck police headquarters in the Egyptian capital, killing four people, the health ministry said. State television had earlier reported that one person was killed and 15 wounded in the second bombing, but a health ministry official told AFP there had been no deaths. He said the makeshift bomb had been planted near the entrance to the metro station Dozens of people are feared injured after the first bomb blast, which left a huge crater in the ground. Egyptian emergency personnel and civilians gather at the site of a car bomb explosion outside the Cairo police headquarters. The explosion sent a large plume of smoke billowing across the Egyptian capital's skyline and left a deep crater in the street. The attack came a day before police were to deploy across the capital for the third anniversary of the 2011 uprising against Hosni Mubarak, with Islamists calling for mass protests against the new regime. A witness who lives in an apartment about 200 metres from the police building said he had been woken up by the explosion. "My building shook," Yahya Attiya said. It was not immediately clear how the car bomb was brought so close to the police headquarters, which is surrounded by a high metal fence that was partially destroyed in the blast. The explosion left a large crater at the gate, and badly damaged the building's facade as well as that of a nearby Islamic museum. The damaged building of Cairo's police headquarters after a car bomb explosion. Riot police pushed back hundreds of onlookers, some of whom chanted slogans against the Muslim Brotherhood. "It was a car bomb," interior ministry spokesman Hany Abdel Latif told AFP. Pictures from the scene showed the facade of the police HQ turned to rubble. Egyptian police stand in front of a destroyed car after a car bomb explosion struck the Cairo police headquarters. Egyptian state TV reported that casualties were being rushed to Ahmed Maher & Gomhuria hospitals as security forces converged on the area. A large number of ambulances were on hand. There were also reports of gunfire in the area immediately after the blast. Millions protested against the rule of Morsi and the Brotherhood over the summer, prompting the coup. An Egyptian man carries an injured girl at the site of a car bomb explosion outside the Cairo police headquarters. The government has been increasingly criticised for its harsh crackdown on any dissent. Since President Morsi's ouster on July 3, security forces have jailed thousands of members of his Muslim Brotherhood, which has also been declared a terrorist organisation. Members of the Egyptian emergency personnel inspect the site of a car bomb explosion. In the latest sign of the air of intimidation against dissent, a court sentenced a blogger, Ahmed Anwar, to three months in prison on Thursday for "insulting the police" and "misusing the internet" over a video he posted on YouTube depicting policemen belly dancing - mocking police for recently giving an award to a well-known belly dancer. The deputy Mideast-North Africa director of Amnesty International on Thursday called on Egyptian authorities to "change course and take concrete steps to show they respect human rights and rule of law," including release "prisoners of conscience." Otherwise, "Egypt is likely to find its jails packed with unlawfully detained prisoners and its morgues and hospitals with yet more victims of arbitrary and abusive force by its police," said Hassiba Hadj Sahraoui. Egypt's Foreign Ministry described the report as "tarnishing the facts" and said the government respects human rights while it is engaged in "combating terrorism."