At least five people have been killed and more than 70 wounded in three separate bombings in the Egyptian capital of Cairo. The first attack hit the main headquarters of the Egyptian police, shattering windows and leaving a gaping hole in the street. No one has claimed responsibility, but a Sinai-based militant group that carried out previous attacks on police released a statement threatening further violence. The military government has used previous incidents to increase its crackdown on the Muslim Brotherhood. In a statement, the Brotherhood said it “strongly condemns the cowardly bombings.” The attacks come one day before the third anniversary of the launch of the uprising that ousted Hosni Mubarak.