A tobacco store clerk was pistol-whipped during a robbery involving eight people, some who were armed with handguns, on Thursday night, Palo Alto police said.

The theft occurred at the Raw Smoke Shop, located at 265 California Ave. in the California Avenue business district. Police dispatchers received a call at about 9:54 p.m. from the clerk. Officers responded immediately, but the robbers had already fled the scene, police said in a press release.

The group entered the open business just before closing time. The clerk, who is in his 50s, was the only person in the store at the time. At least two of the people, and maybe more, were holding handguns. One of the robbers ordered the clerk to the ground and another pistol-whipped him in the back of the head, he told police.

The clerk stayed on the ground for the remainder of the robbery. The group stole merchandise and the cash register, which contained an undisclosed amount of money. They fled the scene in an unknown direction. The clerk couldn't see whether they left on foot or in a vehicle, police said. He suffered minor injuries to his head but declined medical attention.

Surveillance cameras in the store captured images of all eight people, who each wore a face covering. The clerk could not provide any further description.

Detectives are actively investigating the robbery. There have been no recent similar cases in Palo Alto, police said.

Anyone with information about this incident is asked to call the department's 24-hour dispatch center at 650-329-2413. Anonymous tips can be emailed to [email protected] or sent by text message or voicemail to 650-383-8984.