A bomb went off near a military intelligence facility north of Cairo on Sunday, wounding four soldiers, security officials said.

The explosion occurred in Sharqiya province in the Nile Delta, and destroyed the front compound wall of the building, officials said in a statement.

It is the third bomb attack in Egypt in less than a week: on Tuesday, a suicide car bomber killed 15 people at a police compound in Mansoura, north of Cairo, and on Thursday, a bomb in Cairo wounded five people on a bus.

In a statement, the army called Sunday's attack “a continuation of cowardly terrorist acts”.

The day after the attack in Mansoura, which was claimed by al Qaeda-inspired jihadists, Egypt's military-installed authorities accused ousted president Mohammed Morsi’s Muslim Brotherhood and declared the group a "terrorist organisation".

But the Brotherhood said in a statement that “it is innocent of any violent incident that has (been) or will be committed”.

The “terrorist” designation means hundreds of thousands of members of the Islamist organisation could face prison sentences if they stage protests or are found carrying Brotherhood recordings or literature.

Since Morsi's ouster by the military on July 3, security forces have launched a crackdown on the group, resulting in more than 1,000 deaths and thousands of arrests of the toppled president's backers.

France24