Egyptian security forces killed six gunmen in a raid on a village in North Sinai early on Sunday, witnesses say, as the military pressed a campaign against Islamist militants in the lawless peninsula.

State television reported three soldiers were killed in the exchange of fire, but security officials told AFP they had died in a road accident elsewhere in Sinai five hours before the raid on the village of El-Jurah.

“The security forces raided a small house in the village, and there was an exchange of fire,” said one witness, who requested anonymity.

“They killed six people and left the bodies, and came back with ambulances and a fire truck to retrieve them,” he said.

Another witness, who described the gunmen as “strangers” to the village, said the six men were killed when security forces entered a home in which they were hiding.

“They died in an exchange of fire,” he said.

Witnesses said no troops appeared to have died in the raid.

The military had conducted an air strike on the village on Wednesday morning but apparently missed its target.

Sunday’s raid came as the military continued to send tanks and armoured vehicles to Sinai in an unprecedented campaign to capture or kill militants responsible for an attack on an army outpost that killed 16 soldiers last weekend.

It had claimed that it killed 20 militants in Wednesday’s air strikes, but witnesses said the helicopter attacks – the first in Sinai in decades – killed no one.

On Friday, official media reported that the security forces had arrested six “terrorists” in the town of Sheikh Zuwayid, 15km from the border with Gaza.

Their relatives told AFP they were devout Muslims who had nothing to do with the attack on the soldiers, and had been sleeping in their homes when masked soldiers and policemen burst in.

Some of the men, who appeared to belong to the ultra-conservative Salafi branch of Islam, had been jailed without charge under ousted president Hosni Mubarak after a spate of bombings of tourist resorts between 2004 and 2006.

The military campaign has seen the largest build-up of troops in the Sinai since Israel returned it following a peace treaty that restricted Egyptian military presence in the peninsula.

The military believes that the Islamist Bedouin militants work with radical extremists in the neighbouring Palestinian Gaza Strip.