At least three policemen, one security guard and a civilian were killed and a number of other people injured in an attack by militants in Egypt's North Sinai province on Monday, the interior ministry said.

The militants attacked a security post securing a National Bank of Egypt (NBE) branch in Arish, the provincial capital, with explosives and guns, a statement said.

The militants raided the bank branch and stole an amount that had yet to be valued, the statement said. Forces were searching the area for the perpetrators and had defused some explosives.

Egypt is fighting an insurgency against militants affiliated with Islamic State in the northern part of the Sinai Peninsula where hundreds of security forces have been killed since 2013 when Islamist president Mohamed Mursi was ousted following mass protests against his rule.

The militants fired shots randomly in the street as if they were celebrating, with some of them raising their black flags (of Islamic State). They roamed the streets for about 20 minutes then disappeared

Witnesses said armed militants in five cars fired on security forces near a church and the NBE branch before fleeing the scene.

"The militants fired shots randomly in the street as if they were celebrating, with some of them raising their black flags (of Islamic State). They roamed the streets for about 20 minutes then disappeared," said Alaa Lotfy, a shop owner in the area who witnessed the clashes.

At least 24 militants and six soldiers were killed on Sunday in attacks on military outposts in North Sinai.