CAIRO—ISIS terrorist group ambushed a checkpoint in the restive northern part of Egypt’s Sinai Peninsula on Saturday, killing at least five troops from the security forces, officials said. At least six other troops were wounded in the attack in the town of Sheikh Zuweid and taken to a military hospital in the Mediterranean city of el-Arish, they said. Security personnel killed three terrorists in the firefight, and the area was reinforced, the officials added, speaking on condition of anonymity because they were not authorized to brief the media. Egypt has been battling terrorists in the northern part of Sinai Peninsula for years. Violence and instability there intensified after the 2013 military ouster of Mohammed Morsi, an elected but divisive Islamist president, amid nationwide protests against his brief rule. The terrorists carried out numerous attacks, mainly targeting security forces, minority Christians and those who they accuse of collaborating with the military …