Ten Egyptian soldiers were killed in two roadside bombings as they clashed with Islamic State group jihadists in the Sinai Peninsula, the military said on Thursday.

An Egyptian Coptic priest was shot dead Thursday in the Sinai Peninsula where authorities are battling a jihadist insurgency, officials said, in an attack claimed by the Islamic State group.

A Russian passenger plane with 224 people on board crashed in a mountainous part of Egypt's Sinai Peninsula on Saturday, leaving "many" dead including 17 children, officials said.

The chartered plane had taken off from the south Sinai resort of Sharm el-Sheikh bound for Saint Petersburg and lost contact with air traffic control 23 minutes later before crashing in the restive peninsula.

Four Egyptian soldiers where killed by a roadside bomb on Thursday in the Sinai Peninsula, where the army is battling an Islamist insurgency, the military said.

One officer and three soldiers died in the attack on their vehicle near the border town of Rafah, a military spokesman said on his Facebook page.

An Egyptian jihadist group released video footage on Tuesday that it said showed the execution of two army informants in the insurgent flashpoint of the Sinai Peninsula.

Seven Egyptian soldiers were wounded Friday in an explosion near El-Arish, a week after a deadly attack in the same area of the Sinai peninsula killed 30 soldiers, a security official said.

"Two officers and five soldiers were wounded in a bomb explosion against their vehicle south of El-Arish," the capital of North Sinai province, the source said.

The decapitated body of a man was found Friday in a town in Egypt's Sinai Peninsula, security officials said, the latest in a series of beheadings allegedly carried out by jihadists.

Local residents found the body on the side of a road in Sheikh Zuweid, near North Sinai's provincial capital of El-Arish.

An Egyptian soldier was killed Wednesday when a roadside bomb targeted an armored vehicle in the restive Sinai Peninsula, medical and security officials said.

Four soldiers were also wounded in the attack near the north Sinai capital of El-Arish, the officials said.

Egyptian troops on Friday killed a prominent militant in the restive Sinai Peninsula where Islamist fighters have increasingly targeted security forces since last year's ouster of president Mohammed Morsi.

Nour al-Hamdeen was "one of the most prominent and dangerous extremists," military spokesman Colonel Ahmed Ali said in a statement.

The Egyptian army said Wednesday it had foiled a plan by Palestinian Islamist movement Hamas to attack a strategic security building in North Sinai, where militants have increased activity in recent months.

A member of the movement revealed the plan when the army interrogated him, military spokesman Colonel Ahmed Ali said in a statement.