A woman waiting for a bus in Gaithersburg, Md., early Friday was pulled into a wooded area and sexually assaulted, officials said.

The woman told police she was at a bus stop on Watkins Mill Road, near Travis Lane, at 5:30 a.m., when the suspect approached her. He grabbed her, forced her away from the bus stop and attacked her, said Sgt. Rebecca Innocenti, a spokeswoman for the Montgomery County Police Department.

The suspect then fled the area, and the woman called police.

Police officers and search dogs looked for the suspect but did not find him.

The woman was taken to a hospital. There is no indication that she knew the attacker, Innocenti said. The victim is cooperating with detectives, Innocenti said.

Anyone with information about the case is asked to call 240-773-5050. Those who wish to remain anonymous, or to be eligible for a possible reward of up to $10,000, can call 1-866-411-TIPS (8477).