HAYWARD -- A 19-year-old Oakland man was shot once in the stomach outside a Mission Boulevard karaoke bar early Sunday in the most serious of three nightclub-related incidents over the weekend, police said.

Two other people were beaten -- one pistol-whipped -- in front of the Karaoke Box near Sunset Boulevard around 1:30 a.m., and police arrested two people who were driving away from the scene.

According to Lt. Roger Keener, police found firearms in the vehicle, and the men are being held on weapons charges as investigators determine if there is evidence that they fired the shots. Several shots were fired, he said, possibly from more than one gun.

Witnesses were not being cooperative, Keener said.

The victim's wound is not considered life-threatening.

Shots also rang out early Saturday in the parking lot behind the Me Restaurant and Lounge on B Street in downtown Hayward, police said.

It appears the shots were fired in the air during a skirmish that left one man badly beaten, possibly with a broken nose, shortly before 2 a.m., Keener said. Six people were arrested on suspicion of being drunk in public, and one faces narcotics charges.

Keener said the beaten man was "belligerent and uncooperative" before being taken to a hospital. They found five shells from either a 9 mm or .380-caliber handgun, he said.

Witnesses told police that the involved parties had been at the nightclub for a "Fantasy Fridays" event promoted by radio station WiLD 94.9.

Around 12:20 a.m. Sunday, police were called to what was described as a large fight at the Bijou Restaurant and Bar, also on B Street downtown. The victim also was uncooperative and refused medical attention. Two people were arrested on charges of being drunk in public.

Anyone with information about these to crimes may contact police at 510-293-7000.

Contact Eric Kurhi at 510-293-2473. Follow him at Twitter.com/erickurhi. Read his blog at IBAbuzz.com/hayword.