Cairo: Egypt’s military says it has destroyed eight vehicles loaded with weapons, ammunition and explosives, and killed militants in the western desert, after they crossed borders with neighbouring Libya.

The air attack comes a few days after authorities officially announced that at least 16 policemen were killed in a brazen ambush by militants in the Al Wahat Al Bahriya area, about 135 kilometres southwest of Cairo.

Military spokesman Col. Tamer Al Rifai said in a statement on Monday that air strikes destroyed eight vehicles and killed suspected militants, without elaborating.

Friday’s attack took place near Egypt’s vast western desert, where a previous series of attacks were blamed on militants pouring in from Libya.

Egypt has long contended that weapons smuggled across the porous desert border with Libya have reached militants operating on its soil.

Meanwhile, the Palestinian group Hamas has said three Palestinians went missing from a tunnel between Egypt and the Gaza Strip in mysterious circumstances on Monday.

“Three Palestinian workers disappeared inside one of the tunnels on the Palestinian-Egyptian border and the security forces are investigating to locate their whereabouts,” the interior ministry in Gaza City said in a statement.

A number of Gazans have died in tunnel collapses in recent months, but there were no reports of any such incident on Monday.

One witness said that a group of masked gunmen snatched the three and took them across the border into Egypt’s Sinai Peninsula.

The account of the witness, who spoke on condition of anonymity, was not confirmed by authorities.

Egyptian security forces have been fighting a branch of Daesh in the Sinai, and the extremists have recently stepped up their attacks.

In August, a suicide bomber killed a Hamas guard along Gaza’s border with Egypt in what was described as a rare Islamist attack against the Palestinian group.

In 2015, gunmen seized four Hamas members from a bus bound for Cairo from the Gaza Strip in the Sinai near the border.

Egypt has cracked down on tunnels crossing from Gaza into the Sinai, and Hamas has agreed to improve security along the border.

Tunnels between Gaza and Egypt are typically used for smuggling.