Thirty suspected militants were killed and another 15 injured in a series of military airstrikes in North Sinai on Monday, the biggest operation yet in the Egyptian army's ongoing offensive against militants in the restive peninsula, according to reports from Reuters and AP.

The strikes took place in the North Sinai cities of Sheikh Zweid and Rafah, as well as in the eastern and southern parts of Al-Arish, said Reuters' Aswat Masriya news website.

Security sources told Aswat Masriya that another 16 were arrested during the operation.

The armed forces have yet to release an official statement from their spokesman.

Dozens of militants have died in recent strikes as the military has launched a campaign to battle a growing insurgency in North Sinai.

Attacks on police and army targets in the region have intensified following the ouster of Islamist president Mohamed Morsi last July, with scores of police and army personnel killed.

Recent attacks in Cairo and the Nile Delta have been claimed by the Sinai-based militant group Ansar Bayt Al-Maqdis, an Al-Qaeda affiliate.

Four explosions hit police targets in Greater Cairo on Friday 24 January, killing six and injuring at least 80.