One person has been killed after a powerful explosion hit the Italian consulate in the centre of Cairo, according to Egypt's health ministry.

The force of the blast, which a security official said was caused by a car bomb, shook the building in the downtown area of Egypt's capital.

A spokesman for the health ministry said four people were wounded, with the identity of the person killed not immediately clear.

There has been no claim of responsibility so far.

State news agency MENA cited a witness as saying the explosion has caused widespread damage to the building, and quoted a security source who said preliminary investigations indicate the attackers placed a bomb underneath a car and remotely detonated it.

An Associated Press journalist on the scene said the blast heavily damaged several floors of the building, leaving a gaping hole with bricks falling from it and its red facade peeling off.

Charred car parts could be seen scattered in the street.

A charred, baseball-size piece of an engine was also found on a parallel street.

Underground water pipes were ruptured by the explosion, flooding the area.

Italian Foreign Minister Paolo Gentiloni said his country will not be intimidated by the bombing.

He wrote on Twitter: "Bombing against our consulate in Cairo, there are no Italian victims.

"Our thoughts are with the people affected and with our personnel. Italy will not let itself be intimidated."

The consulate was closed at the time, but the building is located at one of the busiest intersections in Cairo, a major road that connects Ramsis Square to the heart of the city.

Even on a weekend morning in the middle of the Islamic fasting month of Ramadan the area where the explosion happened would have been crowded with cars, pedestrians and mini-buses.

Hundreds of soldiers and policemen have been killed in attacks since the army ousted Islamist president Mohamed Morsi in 2013.

Diplomats told AFP they had been warned months ago by police that embassies could be targeted, but it was not clear if this was based on specific intelligence.

At least one Western embassy has recently relocated because of security concerns.

The consulate attack comes less than two weeks after suspected militants assassinated the country's top prosecutor in a car bombing in Cairo.

In Sinai, jihadists loyal to Islamic State group launched a wave of attacks on 1 July that left at least 21 soldiers dead.

IS, which controls large parts of Iraq and Syria, has called on its affiliates to attack Western targets.

The attacks in Sinai prompted President Abdel Fattah al Sisi to pledge tougher anti-terrorism laws which have caused controversy among journalists and rights activists.