CAIRO, Nov 10 (Aswat Masriya) - Four "extremists" were killed Monday in a military aerial bombardment over North Sinai's city of Sheikh Zuweid.

Apache helicopters heavily bombed several targets in villages south of Rafah and Sheikh Zuweid. Eye-witnesses told Aswat Masriya that the helicopters violently bombed a number of "criminal hotbeds", and assembly locations for "extremist" groups.

Meanwhile, security sources said that 55 combat groups will be dispatched to Sinai over the next few days to take part in security campaigns to counter extremist groups. The number will later rise to 110 combat groups to "end terrorism in Sinai".

At least 30 military personnel were killed in a suicide blast which targeted a security checkpoint in Sinai's Sheikh Zuweid on Friday, in the worst militant attack since the ouster of Islamist President Mohamed Mursi last year. The explosion also caused damage to two military vehicles.

Shortly afterwards, a separate attack by unidentified gunmen on a security checkpoint in al-Arish killed three more security personnel.

President Abdel Fattah al-Sisi declared a three-month state of emergency and a nighttime curfew in parts of the Sinai Peninsula in response to the deadly attacks.

Militants have stepped up attacks targeting security forces in Egypt, particularly in the Sinai Peninsula, since the army's ouster of President Mohamed Mursi in July 2013, which followed mass protests against his rule.

Ansar Beit Al-Maqdis, a jihadist group based in Sinai, previously claimed responsibility for several attacks against Egypt's security forces after Mursi's ouster in July 2013, including an attempt in September, 2013 to assassinate the interior minister as well as several attacks targeting security headquarters and convoys.

A fact-sheet prepared by Egypt's ministry of foreign affairs put the death toll for terrorism acts which took place since January 2011 and until April 2014 at 971, including 664 security personnel.