Two Egyptian policemen were killed late on Sunday when unknown assailants attacked a security checkpoint on the outskirts of the Suez Canal city of Ismailia.
In another drive-by shooting, gunmen riding a microbus opened fire at the checkpoint, killing two conscripts, according to Ahram's Arabic news website.
Two policemen were also killed after a checkpoint was attacked on the Cairo-Ismailia road last week. Last month, three policemen were killed in the Nile Delta city of Mansoura when four assailants on motorcycles opened fire at them.
Egypt has been gripped by unrest since the army overthrew Islamist president Mohamed Morsi on 3 July amid mass protests against his rule.
Armed attacks on security units have been occurring regularly across the country since then, particularly in strategic areas with a heavy police and military presence, such as the Suez Canal cities and North Sinai.
More than 100 soldiers have been killed in the Sinai Peninsula since early July, the army said in September.