ALAMEDA -- Five robbers chased a man and set upon him outside the Alameda Police Department early Sunday morning, repeatedly punching and kicking him when he tried to escape after he was initially confronted at gunpoint.

The 22-year-old victim, who lives in Alameda, told police he had just exited the 7-Eleven at Lincoln Avenue and Oak Street at 1:35 a.m. when a man stepped up to him in the parking lot, pointed a black semi-automatic handgun at his face and demanded his money.

When the victim refused, the man struck him across the mouth with the firearm, Alameda police Lt. Ted Horlbeck said.

The victim fled from the parking lot and ran toward the police station -- which is located at the same intersection -- pursued by the suspect, as well as by two other men and two women.

The group caught up with the victim on the Lincoln Avenue side of the station near the department's rear driveway, where they tackled him and all five suspects repeatedly punched and kicked him, Horlbeck said.

The victim was transported to Highland Hospital in Oakland, where he was treated for a skull fracture and multiple cuts and bruises, police said.

The victim could not provide a detailed description of the suspects. Each man was described as about 20 years old and each was wearing dark clothing. The women were also as in their 20s with dark hair. Each stands about 5 feet 6 inches tall and has a medium build.

The suspects fled in possibly a green 1990s Dodge Ram pickup and in a newer model Dodge Challenger, police said. Both vehicles pulled up during the assault and were apparently driven by accomplices of the suspects.

Alameda police ask anyone with information to call 510-337-8340.

Reach Peter Hegarty at 510-748-1654 or follow him on Twitter.com/Peter_Hegarty.