Three people were injured — including a 12-year-old boy — in two separate San Francisco shootings that occurred about five hours apart on Sunday, police said.

A 23-year-old man was shot and a 12-year-old wounded by fragments of shattered glass after gunfire erupted in the unit block of Osceola Lane around 2:12 p.m.  Two men, aged 18 to 25, approached the victim and fired several shots.

The victim was shot in the hand, leg and foot, police said. A stray bullet hit a nearby residence, shattering glass that injured the boy.

The adult was taken to the hospital with life-threatening injuries, police spokesman Officer Albie Esparza said. The boy's injuries were not life threatening.

The shooting may be gang related, Esparza said.

Around 7 p.m., a 21-year-old man was shot while entering a liquor store in the 500 block of Bayshore Boulevard. The victim got a ride to San Francisco General Hospital and his injury was not life threatening, police said.

No arrests have been made, Esparza said Monday.

Witnesses are urged to call police at their anonymous tip line at (415) 575-4444 or by text at TIP411.

rnagle@sfexaminer.com