Updated

Militants in Egypt's northern Sinai Peninsula struck a police bus with a roadside bomb on Monday, wounding nine people and killing with a gunshot to the head a young conscript who had survived the blast, security officials said.

The 21-year-old had jumped from the moving bus after the explosion and was likely kidnapped by militants who shot him and dumped his body on the side of the road, they said. One of the wounded in the bus attack was a civilian, the rest were conscripts.

The blast on the outskirts of el-Arish, northern Sinai's provincial capital, came amid a counterinsurgency operation by Egypt's military and police in the volatile desert region.

The bus had carrying conscripts from the border town of Rafah, near the Palestinian Gaza Strip, to el-Arish and was escorted by an armored police car. The bomb was set off by remote control, said the officials who spoke on condition of anonymity because they were not authorized to speak to the media.

The attack comes as Egypt's military presses its largest offensive in years against militants in Sinai in response to attacks the army says have killed more than 100 policemen and soldiers since the July coup that ousted Islamist President Mohammed Morsi from power. The deadliest attack took place Aug. 19 when unidentified gunmen pulled 25 police conscripts off minibuses and shot them dead on the side of the main road linking Rafah to el-Arish.

While the military says it is only targeting militant hideouts in northern Sinai, security officials have not commented about alleged civilian deaths in the latest offensive. Few journalists have direct access to what is happening in Sinai because of security restrictions and concerns, forcing many to rely on statements by officials.

A statement purportedly released by the Sinai-based Islamic militant group Ansar Jerusalem late Sunday said the military had killed seven civilians, among them four children, in the town of Sheikh Zuweyid in northern Sinai during a military operation there on Friday. It said the children, aged one to seven years-old, died from "tank bombardment." The statement, which listed the names of those allegedly killed, said a widowed mother and another woman also died in the military assault. The militant group added that a 23-year-old man was run over by an armored vehicle in front of his family in another incident that day, and warned retaliation for the "blood of innocent Muslims".

"This heinous massacre committed by the Egyptian army in this town is conclusive evidence of what we said earlier, which is that the goal of the army in this operation is the forced displacement of people in Sinai from the Zionist border region," the statement said.

Ansar Jerusalem's post on militant websites also included gruesome images of the dead children, some with serious injuries to the head.

In a case that highlights the volatility of the situation in Sinai, an Egyptian journalist is being tried in a military court on charges of spreading false information about the army's operations there. Freelancer Ahmed Abu-Draa, a resident of Sinai, stands accused of lying about the army for saying it attacked mosques and was relocating families in Sinai.