Egyptian Apache airstrikes killed on Wednesday 21 takfiri elements in the Sinai Peninsula, east of the capital city of Cairo, Al-Bawaba News cited high-ranking military officials as saying. The officials said six terrorists were killed and an explosives depot was wholly destroyed as an Apache raid targeted a terrorist hotbed, southern the North Sinai city of Rafah, where affiliates of Wilayat Sinai terrorist group were gathering. Another raid targeted a farm near the Mediterranean Sea, also in Rafah, leaving 15 terrorists killed, the sources added. Egypt has launched a severe military crackdown against terrorists in the restive Sinai following a string of deadly terrorist attacks claiming hundreds of lives among security personnel and civilians. Terrorist bombings have largely increased across Egypt since former president Mohamed Morsi was ousted July 2013 amid military-backed mass street protests. The Egyptian military started November 2014 the construction of a buffer zone on the eastern border with the Islamist-run Gaza Strip in a bid to thwart smuggling weapons and militants into the volatile peninsula.