The search for missing Hayward nursing student 26-year old Michelle Hoang Thi Le dragged onto Thursday with the police failing to find any clues about her whereabouts despite issuing some search warrants and interrogating some people.

Le, a student of Samuel Merritt University, disappeared without a trace around 7pm last Friday. Her friends and colleagues said Le had stepped out during a class break at Kaiser Permanente Hayward Medical Center, after which she was never seen.

The police said she could not be reached on her cell phone and her car was found parked a few blocks away from the medical center.

The authorities have issued at least four search warrants and have questioned a few people, including her friends, family, co-workers and neighbors, who knew Le closely.

The police are also studying Le's phone records and examining the surveillance video in the Kaiser parking area where Le's car was supposed to be parked.

However, Le's car was found parked a half-mile away on Ponderosa Court. A laptop was found in the car, but there was no sign of foul play.

The detectives are also exploring a couple of theories about her strange disappearance. They haven't ruled out foul play.

A $20,000 reward announced by Le's family for anyone who could provide information leading to her safe return.

Le is still being treated as a missing person. She is described as 5'6 tall, with black hair and brown eyes.

If you have any information on Le, please contact Hayward Police Department at 510-293-7000.