LAHORE, Pakistan—A passenger train crashed into a college van carrying female students at an unmanned railway crossing in eastern Pakistan on Tuesday amid smog, killing three people and injuring seven others, police said. The accident happened in the district of Sheikhupura in the Punjab province, according to Rana Shakeel, a senior district administration official. He said the dead and injured were taken to a nearby hospital. Footage on social media showed the badly destroyed van near the railway tracks. Angered over the accident, residents briefly blocked the railway tracks, delaying some trains. Authorities said they restored the train service and officers are investigating to determine whose negligence caused the accident. Train accidents are common in Pakistan, where successive governments have paid little attention to improving the poorly maintained signal system and aging tracks. In June, an express train barreled into another train that had derailed in southern Pakistan, killing about …