Egyptian security forces killed 13 militants on Friday during a raid on a farm hideout in the Western Desert region where a police convoy was attacked a week earlier.
"They took a house in the farm as a temporary hideout faraway from security monitoring to receive newly recruited elements and train them and prepare the explosive devices," the interior ministry said.
The ministry statement gave no details on the militants, but Egyptian forces have been battling several armed extremist groups, mainly an ISIL affiliate that has killed hundreds of police officers and troops in the northern Sinai Peninsula since 2013.
The raid was in an area near the Assuit-Kharga desert highway, about 400 kilometres south-west of Cairo in New Valley province, which shares a long border with southern Libya. Southern Libya has become a hideout for militant brigades taking advantage of the security vacuum there.
After clashes with the militants, 13 bodies were recovered at the farm, some wearing militant uniforms. Security forces also recovered weapons, suicide-bomb belts, cash and ammunition, the ministry said.
The statement did not say whether the group was linked to the militants who attacked police on October 21 in a remote area of Giza governorate, 135km outside Cairo, where they were searching for a militant hideout.
"Security forces dealt a severe blow to the terrorist elements in revenge for the blood of the men who were martyred last week in the oasis," the state news agency Mena quoted a high-level security source as saying.
The interior ministry put the toll from last week's attack at 16 but security sources said it was at least 50.
Most of Egypt's violence is centred in the northern Sinai, where a local group, Ansar Bait Al Maqdis, pledged allegiance to ISIL in 2014. It had mostly targeted security forces with ambushes and suicide attacks, but has spread to other areas of Egypt outside the peninsula.
The Western Desert region has long been for a route for smugglers and arms coming across Libya's porous border. The Egyptian military said on Monday its air force hit eight four-wheel-drive vehicles carrying arms and explosives at the western border with Libya, killing the militants on board.