CAIRO, Sept 20 (Aswat Masriya) - Security forces launched a security campaign south of North Sinai's Sheikh Zuweid on Saturday killing a leading member of the Sinai-based militant group Ansar Bayt al-Maqdis who was described by army sources as one of the "most dangerous extremists".

He was an "expert" in planting explosives ambushing vehicles of security forces, sources said, adding that he had received training in Gaza Strip on how to plant mines and improvised explosive devices (IEDs).

Three "extremists" were also arrested while planting an IED, sources added, and a car bomb was destroyed.

Six police personnel were killed when an armoured vehicle exploded on the Rafah-Arish road in North Sinai on Tuesday.

One police officer and five policemen were killed in the explosion which occured as a joint security convoy of policemen and armed forces personnel was passing through the Rafah road, according to an interior ministry statement. The attack also left two people injured.

Egypt's security forces have intensified their security measures in North Sinai in reaction to repeated militant attacks that target army and police officials, which rose significantly since the military ouster of former President Mohamed Mursi last year.

One officer and 10 conscripts were killed two weeks ago in an attack on a security convoy in North Sinai.

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.