OAKLAND -- Three unrelated shootings across East Oakland from Thursday night into Friday morning left one man dead and three hospitalized, police said.

The deadly shooting happened after two groups of people standing outside got into a physical confrontation at about 5:45 a.m. Saturday in the 8900 block of Birch Street, police said.

The victims lived in the immediate area and are possibly related, police said. During the confrontation, someone in the opposing group drew a gun and fired multiple shots, fatally wounding a 22-year-old man and hitting another, 24-year-old man.

Police responded to the scene and both men were taken to a nearby hospital. The younger victim died. The older victim was suffering non-life-threatening injuries.

Police did not release any suspect information Saturday morning and no suspects were in custody.

The killing was the 71st homicide in Oakland this year. At the same time in 2011 there had been 73.

In an earlier shooting, a robbery victim was shot by multiple suspects after they accosted him and he turned out to have no money, police said. That happened at about 1:20 a.m. in the 2300 block of 90th Avenue.

The night before, a man was shot at about 7:30 p.m. during a robbery at the intersection of 35th and Allendale avenues, police said.

Both robbery victims are expected to survive their injuries.

Police and Crime Stoppers of Oakland are offering up to $15,000 in reward money

Anyone with information can call investigators at 510-238-3821 or at a tip line at 510-773-2805 or Crime Stoppers at 510-777-8572 or 510-777-3211.

Staff writer Harry Harris contributed to this report.