OAKLAND — Four people were wounded early Sunday after an argument at a downtown sports bar escalated into a shooting, police said.

None of the victims sustained life-threatening injuries, and at least one was treated and released at a hospital.

Two of the victims were 26-year-old women, one from San Leandro and the other from Hayward.

Two San Leandro men, ages 25 and 29, were also wounded.

Police said the shooting happened about 12:33 a.m. Sunday inside the Halftime Sports Bar, 316 14th St., where the victims were attending a birthday party.

Police said the suspect got into an argument with the 29-year-old man that got more heated and ended with the suspect pulling a gun and beginning to shoot. It was not clear if the two men previously knew each other or if the gunman had been attending the party.

It was not immediately known how many people were inside the bar when the shooting happened, but the four were the only ones hit by gunfire as those inside began fleeing, police said.

The four shooting victims were taken to different hospitals for treatment.

The gunman fled in a vehicle after the shooting, and is still being sought by police.

Police later stopped and detained a 38-year-old Oakland man in connection with the shooting, but after questioning, he was released.

Police and Crime Stoppers of Oakland are offering up to $20,000 in reward money for information leading to the arrest of the gunman. Anyone with information may call police at 510-238-3426, or Crime Stoppers at 510-777-8572.

Check back for updates.