Six, including at least one civilian, were killed on Sunday when a bomb-laden vehicle exploded near the Third Police Station in North Sinai's Al-Arish, a common target for militants in the restive peninsula.
A suicide bomber sought to ram a van laden with explosives into a checkpoint in the vicinity of the police station, the interior ministry said. The vehicle exploded when police forces opened fire at it, killing at least five policemen, according to the statement.
Health ministry spokesman Hossam Abdel-Ghafar later told Ahram Online the death toll had risen to six, with at least one civilian among the deceased. He said 40 were also injured.
Both policemen and civilians were injured in the blast, the interior ministry's statement also said.
Final death and injury tolls have yet to be announced, with counting still ongoing, Abdel-Ghafar said.
An exchange of gunfire and ambulances were heard following the huge explosion, which reportedly created a large crater and shattered house windows near the police station.
Militant group Ansar Beit Al-Maqdis has claimed responsibility for the attack, which came hours after another operation that they also claimed.
A first lieutenant, a sergeant and four conscripts were killed earlier on Sunday when their armoured vehicle was attacked on the highway from Al-Arish to Sheikh Zuweid, North Sinai. Two other soldiers were injured and taken to the Arish military hospital.
Later in the day, a third attack on a checkpoint in Rafah left three security personnel injured, after unknown assailants opened fire at them.
So far, at least 12 have been killed in Sunday's militant attacks in North Sinai.
Ansar Beit Al-Maqdis has claimed many attacks against the army and police in Sinai.
Last Friday, the group, which has pledged allegiance to Islamic State militant group, published a graphic video showing the execution of a 20-year-old soldier kidnapped during the group’s 3-April attack on security checkpoints that killed 15 soldiers.
The video also included the beheading of a local man from Sinai for allegedly collaborating with Israeli spy agency Mossad.
Egypt's army has been fighting a decade-long militant Islamist insurgency, which has spiked since the ouster of Muslim Brotherhood president Mohamed Morsi in summer 2013.
Hundreds of police and soldiers, as well as civilians, have been killed in militant attacks in the past months.