Gunmen killed three policemen in Egypt's Daqahliya, a Nile Delta city northeast of Cairo, on Monday, said an Interior Ministry statement.

Four unknown assailiants shot gunfire at a police security checkpoint early on Monday, according to the statement.  

Attacks against the security forces in Egypt have risen sharply since the military's ouster of Islamist President Mohamed Mursi, leaving dozens of them killed.

In a similiar recent incident, extremist supporters of Mursi attacked a police vechile in Sohag, a governorate south to Cairo, on Sunday, killing one policeman and wounding another.