Egyptian security forces shot dead 24 Islamic State militants in central Sinai, 70 km from the crash site of the Russian passenger plane the group claimed it brought down, security sources said on Monday.
Security sources said they killed the militants as they hid inside a cave in a mountainous area and that they arrested eight of them.
Sinai Province, Islamic State's Egypt branch, is active in North Sinai where two years ago it launched an insurgency and has since killed hundreds of soldiers and policemen. It is rarely active outside that area.
Western governments said it was likely that the Russian airliner that crashed in the Sinai on October 31 killing all 224 people on board was brought down by a bomb and Islamic State claimed it was behind the crash.
Egypt says the bomb theory is premature and that only the conclusion of an official investigation will shed light on what brought down the Airbus 321.
Sinai Province said in a statement on the day of the crash that it had brought down the plane in response to Russian air strikes in Syria.
