Eight Egyptian soldiers were killed in a car bomb attack targeting a checkpoint in Sinai, where the local affiliate of the Islamic State group is leading an insurgency, the army said Thursday.
"A group of armed terrorists attacked one of the security checkpoints in north Sinai," the army spokesman said.
"A car bomb attack, the clashes that ensued and a blast targeting one of the vehicles left eight members of the armed forces dead," he added.
Three jihadists were also killed in the fighting, he said.
"The search operation is ongoing... in the bid to eradicate the remaining jihadists," he added.
The military did not reveal where exactly in northern Sinai the attack had taken place.
There was no immediate claim of responsibility for the attack.
The army has been battling an Islamist insurgency in northern Sinai which has escalated since the military overthrow of Islamist president Mohamed Morsi in 2013.
The government says hundreds of police and soldiers have died in the attacks, which have also hit Cairo and the Nile Delta.
On November 4, gunmen killed a top Egyptian army officer outside his home in the northern Sinai.
Most of the attacks have been claimed by the Egyptian IS affiliate.
Thursday's attack was the deadliest since an assault on a checkpoint killed 12 soldiers and wounded six others in the Sinai peninsula.
IS claimed responsibility for that attack.
The group also said it was responsible for the downing of a Russian plane over Sinai in October 2015 which killed all 224 people on board, most of them Russian holidaymakers.
In February, Egyptian President Abdel Fattah al-Sisi acknowledged for the first time that "terrorism" was behind the crash, although the government has not yet issued an official report on its cause.
Sisi had previously dismissed as "propaganda" the IS claim that it downed the airliner.
The prosecution said last week that Egypt would try 292 jihadist suspects over plots to assassinate Sisi and the Saudi crown prince and for carrying out attacks in the Sinai Peninsula.
The suspects, including 151 currently in custody, were referred to a military court for alleged membership of the "Sinai State", IS's local affiliate.