IS claims bomb attack on Cairo police

IS has claimed responsibility for a bomb attack that has injured 29 people in a Cairo police building.

A police building in northern Cairo has been targeted in a bomb attack, injuring six officers. (AAP)

A powerful car bomb blast that tore through a Cairo police building injuring at least 29 people has been claimed by IS.

Six policemen were among those wounded in the explosion but officials said none of the injuries was life-threatening.

Described by a resident as "like an earthquake", the overnight explosion shook the working-class Shubra district of northern Cairo, severely damaging the front of the police office and shattering the windows of nearby buildings.

The attack came only days after President Abdel Fattah al-Sisi imposed a tough new anti-terrorism law as he struggles with a jihadist insurgency spearheaded by the local branch of IS.

Egypt's interior ministry said in a statement that a car had exploded outside the police building, which houses a centre for investigating threats to national security, in the early hours of Thursday morning.

It said that before the explosion a man was seen parking the car in front of the building and escaping on a motorbike that had followed the vehicle.

Health ministry spokesman Hossam Abdel Ghaffar said six policemen and 23 civilians had been wounded but none of the injuries was serious.

IS claimed responsibility for the attack in a statement posted on an affiliated Twitter account.

"The soldiers of the Islamic State managed to target a police building with a car bomb in the heart of Cairo," the statement said.

It said the attack was revenge for the hanging of six members of its Egyptian affiliate - known as "Sinai Province" - in May.

The main jihadist group in Egypt's restive Sinai Peninsula pledged allegiance to IS, which has seized control of large parts of Syria and Iraq, last November.

The six men were convicted of killing soldiers in attacks carried out in the months after the army's ouster of Islamist president Mohamed Morsi in 2013.

An AFP reporter saw a wide crater left behind by the blast near the four-storey concrete building. The building's windows were blown out and its facade was left cracked and crumbling, while parts of a wall surrounding it were destroyed.

While most of the attacks have centred on Sinai, IS has in recent months carried out more attacks in the capital, including against foreign targets.