CHICAGO — A man followed a woman, dragged her into an abandoned building and raped her early Monday in West Humboldt Park, police said.

At 2:10 a.m., the woman was walking outside when she saw a teenage boy or man follow her for several blocks, according to a Chicago Police Community Alert. The man “disappeared,” police said, and the woman bought cigarettes from someone inside a home and then started walking back the way she came.

The attacker grabbed the woman from behind and dragged her into the back entrance of an abandoned building in the 1100 block of North Keystone Avenue, police said. He punched the woman in her head and sexually assaulted her.

The attacker ran away afterward. The woman went to her friend’s house and was then taken to St. Mary Hospital.

The attacker was described as a black boy or man who was in his late teens or early 20s, police said. He had black hair, was 5-foot-8 to 5-foot-10 and wore a black skull cap, an orange sweater, blue jeans and white Nike Air Force Ones.

Anyone with information about the attack was asked to call police at 312-744-8261.