Hundreds of volunteers searched a canyon in Northern California for a missing nursing student who disappeared almost a month ago, the San Jose Mercury News reports.

More than 450 volunteers scoured the area in and around Niles Canyon in Fremont, Calif., over the weekend looking for 26-year-old Michelle Le, according to the newspaper.

Police are treating the case as a homicide, though Le's relatives say they're holding out hope that they'll find her alive.

Le, of Hayward, Calif., was last seen at around 7 p.m. on May 27 after she took a break during a nursing class at Kaiser Hospital in Hayward. No suspects have been identified in her disappearance.

Investigators said last week that they're looking at new surveillance video from the hospital garage where her car was parked. They haven't said what's on the video.

A $65,000 reward is being offered in the case.

Anyone with information on Le's whereabouts it being urged to call the Hayward Police Department at 510-293-5051.

The Associated Press contributed to this report