The armed robbery at the Beach Side Station at 681 state Route 75 was reported about 10:50 p.m. Tuesday, said San Diego County sheriff's Sgt. Michael Blevins.

The robbers wore hoodies, bandanas over their faces and baseball caps on their heads, Blevins said, adding that one had a black handgun.

After taking money from the cash register, the robbers forced the lone employee into a back office to open a safe, according to the sergeant, who said the employee complied and was then tied up.

The robbers fled on foot southbound on Seventh Street with money from the cash register and the safe, Blevins said. The exact loss was not disclosed.

The bound employee was freed a few minutes later by someone who came into the business, the sergeant said.

Authorities described the robbers as black men in their 20s, 5 feet 7 inches or 5 feet 8 inches and weighing between 160 and 170 pounds.