Egypt's military killed 20 militants in a raid using helicopter gunships in Sinai on Wednesday, a military official said, days after 16 soldiers were killed in an attack attributed to Islamic extremists.

A senior military official in Sinai, who spoke to reporters on condition of anonymity, said "20 terrorists were killed" in Apache helicopter airstrikes and when soldiers stormed Tumah.

"The operation is continuing," he said. Other security officials in the north of the peninsula reported airstrikes near the town of Sheikh Zuwayid, close to the village.