SAN DIEGO -- Two men were detained Tuesday following a sexual assault behind a City Heights bar that sent a woman to the hospital, police said.

Witnesses reported seeing one of the men on top of the woman and the other watching in the parking lot behind El Uno Bar, 3412 University Ave., at around 11 p.m. Monday, San Diego police Sgt. David Jennings said.

Responding officers chased the men to Swift Avenue, where they were put in patrol cars and taken to the police station for questioning, according to Jennings.

The woman, believed to be in her 30s, was taken to the hospital, he said.

"She was beaten up pretty good," Jennings said. "There's not a lot of details yet because it appears she was also pretty intoxicated so we have to wait to talk to her."