Two men were caught on a mall's security camera as they chased a woman through a parking structure, then grabbed and stuffed her into the trunk of a car.

Nearby shoppers seemed to notice the apparent abduction, but none attempted to stop it.

Police on Thursday were still trying to determine the identities of the woman, believed to be in her 20s, and two men involved in the Sunday evening incident at the Corona Discount Mall.

The woman's videotaped reaction upon seeing the men suggested she knew them.

Detective Frank Zellers said the incident was being investigated as a kidnapping.

"It's very discouraging right now and it's really difficult for us, because we don't know who the victim is," he told KCAL-TV. "And it's obvious that some kind of crime occurred. We don't know who the suspects are and who the victim is."

The department had received several calls from witnesses and others in recent days, but had no solid leads, Officer Jesse Jurado said. He said investigators had not yet ruled out the possibility that the incident was a hoax.

A security camera with a view outside the front of the mall recorded the scene as the woman walked from a parking lot to the sidewalk outside the entrance.

When a black Toyota Solara raced up and braked, the woman looked over her shoulder at the car and took off running into a parking structure with the vehicle in pursuit.

Despite a fuzzy videotape image, the woman can be seen running down a parking aisle as two men jump out of the Solara and chase her. One man threw the woman over his shoulder, carried her back to the car and put her in the trunk, which the other man had opened.

A security guard at the mall heard the woman yelling for someone to call the police as she was being stuffed in the trunk, Jurado said.

A handful of shoppers visible in the foreground of the scene appeared to turn their heads and watch the incident. In addition, several motorists drove through the scene.

The car's right front tire was a smaller, spare donut-type tire, police said.

Corona is a Riverside County city of 138,000 about 40 miles southeast of Los Angeles.