A car bomb injured six Egyptian policemen on Thursday as it exploded in front of a police building in Cairo, the interior ministry said, the latest in a wave of militant attacks that has rocked Egypt.
The powerful blast in northern Cairo's district of Shubra came in the middle of the night, an AFP journalist said, as Egyptian security forces are being targeted by Islamic State jihadists waging an Islamist insurgency.
"A man suddenly stopped his car in front of the state security building, jumped out of it and fled on a motorbike that followed the car," the ministry statement said.
"The car exploded, wounding six policemen."
Earlier a security official told AFP that "an attack targeted a state security building".
"The explosion partially destroyed the building," said a colleague on condition of anonymity.
The bombing came just days after President Abdel Fattah al-Sisi ratified an anti-terrorism law which critics claim gives wider powers to police, restricts human rights and muzzles the press.
No group has yet claimed responsibility for Thursday's attack, but Sinai Province, the Egyptian branch of the Islamic State group regularly carries out attacks on security services as part of an insurgency that has swelled since the army's ouster of president Mohamed Morsi in July 2013.
Jihadists say their attacks are in retaliation to a police crackdown targeting Morsi supporters that has left hundreds dead and thousands jailed.
Hundreds more have been sentenced to death after speedy trials, denounced by the United Nations as "unprecedented" in recent history.