DENVER — Police are investigating after four teenage girls said a man who was posing as a police officer patted them down outside an Aurora pharmacy.

KUSA-TV reports (http://on9news.tv/1nlEDFi ) the man allegedly told the teens outside a Walgreens store late Friday night that he was an undercover officer and he needed to pat them down. Investigators say at least one of the teens told them she was sexually assaulted during the search.

The man is described as white or Hispanic, in his mid- to late-20s, 5-foot-8 and about 150 pounds. He was last seen wearing dark jeans, a thin winter coat and carrying a camouflage backpack.

Police also say he had a strong body odor and was riding a blue mountain bike.