A bomber, whose explosives vest failed to detonate, was killed on Sunday as he attempted to attack a group of university students in the Afghan capital of Kabul on Sunday. The police district chief said that five students were wounded in the attack. Nasir Nadery said the attacker, who slipped past two guards, was wearing an explosives vest that failed to explode. The students were inside a private compound where they were taking classes to prepare for university exams. The attack took place in a Kabul neighborhood dominated by ethnic Hazaras, a Shi’ite minority. No one immediately claimed the attack, which resembled previous assaults carried out by the ISIS terrorist group. On Saturday, a Taliban car bomb killed at least three people and wounded two in Kabul in an apparent attack on a foreign contractor company that came despite a further tightening in security across the city. Interior Ministry spokesman Najib Danesh said all those killed and wounded in the explosion were civilians, with no casualties among the contractors. Also on Saturday, the Taliban attacked security positions northwest of Kabul, killing at least five police and setting off a two-hour gunbattle. The Taliban have stepped up attacks across Afghanistan since the US and NATO formally concluded their combat mission at the end of 2014. In the western Ghor province, meanwhile, a roadside bomb killed a young shepherd and wounded five others. Police spokesman Iqbal Nizami said the Taliban planted the bomb in order to target security forces. In the eastern Khost province, police spokesman Basir Bina said a roadside bomb killed two children and wounded another nine.