OAKLAND — A 12-year-old boy and three adults were injured in an East Oakland shooting Sunday morning, authorities said.

In addition to the boy, 45- and 30-year-old men were shot and a 45-year-old woman sustained injury from shrapnel, authorities said. All of them are expected to recover.

Police said the four are part of the same family, but their exact relationships were not confirmed.

The shooting was reported about 12:08 a.m. Sunday outside an apartment complex in the 3000 block of Brookdale Avenue, a residential area in the Lower Dimond area of the city.

Police said the family was having a barbecue when at least one gunman got out of a vehicle and began shooting at the victims from the street. The victims were outside.

Multiple rounds were fired, injuring the four victims and damaging the front of the apartment building.

The shooter fled in the vehicle before police arrived.

The adults, some of whom were hit more than once by the gunfire, were taken to a hospital and the boy, who was wounded in the leg, was treated at the scene, authorities said.

Police don’t have a motive yet for the shooting.

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

Check back for updates.