Islamic militants launched a series of attacks against Egyptian police in the northern Sinai Peninsula on Monday, killing five of them and wounding another 11, security officials said.

They say the militants opened fire on an armored vehicle before setting it ablaze in the city of el-Arish. When reinforcements arrived, the militants set off a roadside bomb. The two attacks killed a total of five policemen and wounded another five, the officials said. Another roadside bomb struck a third armored vehicle near the airport south of the city, wounding six police.

Earlier in the day, Egyptian F-16 fighter jets struck gatherings of suspected militants in different areas across northern Sinai, killing 30, officials said.

The officials spoke on condition of anonymity because they were not authorized to brief reporters.

Egypt has been struggling to combat an insurgency in the northern Sinai that has gathered strength since the military overthrew Islamist President Mohammed Morsi in 2013. Most of the attacks, including an assault on an army post earlier this month that killed 23 soldiers, have been claimed by an Islamic State affiliate.

On Sunday, Egypt's military said its fighter jets destroyed 15 all-terrain vehicles carrying weapons, explosives and "criminal elements" after they were detected getting ready to cross the Libyan border into Egypt. Authorities say militants use the porous border with Libya to smuggle fighters and weapons into Egypt.