Four Egyptian soldiers were wounded on Sunday as a bomb exploded near an army intelligence building.

Four Egyptian soldiers were wounded on Sunday as a bomb exploded near an army intelligence building.

The explosion, which the army said was a "cowardly terrorist" act, comes as the military-installed authorities plan to hold a referendum on a new constitution next month.

Sunday's explosion occurred in the Sharqiya province in the Nile Delta and destroyed the rear compound wall of the intelligence building, the army said, adding four soldiers were wounded.

The blast was the third such attack in less than a week.

But another was averted on Sunday when a bomb was found and defused by experts near the gate in front of Al-Azhar's medical faculty in New Damietta city, north of Cairo, security officials said.

On Tuesday, a suicide car bomber killed 15 people at a police building in Mansoura, north of Cairo. And on Thursday a bomb in Cairo wounded five people on a bus.

Egypt has descended into chaos since the army ousted Muslim Brotherhood’s Mohammad Mursi last July.