Egyptian military airstrikes killed 27 Islamic militants in Northern Sinai early on Friday, in one of the biggest security operations in the region months, security sources said.

Apache helicopters targeted militants from Sinai Province, a group that pledged allegiance to Islamic State, the ultra-hardline militants who have seized swathes of Iraq and Syria, the sources said.

Sinai Province, fighting to topple the Cairo government, has claimed responsibility for coordinated attacks that killed more than 30 security forces in late January.

After that bloodshed, President Abdel Fattah al-Sisi told Egyptians the country faced a long, tough battle against militants.