An Oklahoma City police officer was being held in jail Thursday night after being accused of a string of on-duty sexual assaults in a case described as “disturbing” by the city’s police chief.

Daniel Ken Holtzclaw, 27, a three-year veteran of the Oklahoma City Police Department, was arrested about 3 p.m. Thursday outside Gold’s Gym, 2301 W Memorial Road, on complaints of rape, forcible oral sodomy, sexual battery and indecent exposure. He was being held in the Oklahoma County jail in lieu of $5 million bail.

The arrest was announced at a short-notice 4 p.m. news conference featuring Oklahoma City Police Chief Bill Citty and Oklahoma County District Attorney David Prater.

Holtzclaw is accused of stopping women — some as they walked through neighborhoods — and threatening them with arrest, Citty said. Police said Holtzclaw forced women to expose themselves, fondled the women, and in at least one instance, had intercourse with a woman, Citty said.