A jihadist group operating in the Sinai Peninsula has taken responsibility for executing five more people for collaborating with Israel, after it announced Thursday that it had beheaded four people on the same charges.

Ansar Bayt al-Maqdis claimed responsibility for the execution for espionage of nine Bedouins in all, Israel Radio reported Tuesday.

The radio station said five decapitated bodies had been discovered in the peninsula in recent days, bringing the total number of beheaded corpses found in recent days up to eight after two bodies were discovered in the northern part of the peninsula on Sunday and one on Friday.

The ANSA news agency reported that four, and not five, bodies had been found, citing an Egyptian security source.

Meanwhile Tuesday, a roadside bomb exploded near an armored police vehicle traveling in the restive peninsula, killing 11 police officers, including a senior official, Egyptian security and medical officials said.

The bomb appeared to have been detonated by remote control and it went off as the police vehicle was driving through the village of el-Wefaq, near the Egyptian border with the Gaza Strip, security officials said.

A medical official said the explosion also wounded two officers.

Last week, the Sinai terrorist group announced it had beheaded four Egyptian men who it claimed had spied for Israel. On Friday, villagers in Rafah, on the border with Gaza, discovered the beheaded corpse of a 23-year-old man who eyewitnesses said was kidnapped on Thursday near his house by gunmen driving an SUV.

The severed head was reportedly placed in the mortuary of a nearby hospital as Egyptian police worked with local tribesmen in the restive peninsula to identify the perpetrators.

Then, early Sunday morning, the decapitated bodies of two men were found by Egyptian security forces in a desert area in the northern Sinai peninsula.

The two men had been kidnapped by unknown assailants a day before their bodies were discovered, residents of Rafah told Reuters’ Egyptian website, Aswat Masriya.

In a video released Thursday, Ansar Bayt al-Maqdis claimed responsibility for the executions and said the men had provided intelligence to Israel’s Mossad agency.

The video showed men in black masks beheading the accused collaborators as they knelt on the ground, according to Reuters.

The terror group said that the men provided intelligence to Israel used in a July airstrike on northern Sinai, in which three Ansar Bayt al-Maqdis fighters were killed. The Egyptian army said at the time of the strike that no Israeli aircraft had been in Egyptian airspace.

Two of the executed men served time in Israeli jails for smuggling, and two had said the Mossad had paid them for information, the group asserted in the video.

Earlier this month, the decapitated bodies of four other men were found in the Sinai Peninsula, with Egyptian security forces suspecting they had been killed for aiding the Egyptian army.

Egypt’s military has been carrying out a vast offensive against jihadist groups in the north of Sinai since militants stepped up attacks following the army’s ouster of Islamist president Mohammed Morsi in July last year.

AP, AFP and Lazar Berman contributed to this report.