(09-07) 13:16 PDT SAN FRANCISCO -- A 19-year-old man was shot in the hip outside BART's 24th Street Mission station this afternoon, the latest act of gun violence to plague the Mission District in recent days.

The victim was shot from behind, "like he was running from the suspect," San Francisco police Sgt. Omar Bueno said. Police said they expected the man to survive.

His name has not been released. No arrests have been made, and police did not release a description of the suspect.

Witnesses said the gunfire sent people fleeing in all directions. "I thought it was a firework," said Ray Velasco, 59, a neighborhood resident who was hanging out at the McDonald's on the corner of Mission and 24th Street. "Everybody was running."

Police have increased their presence in the Mission in the aftermath of three fatal shootings over the course of a week. Investigators suspect that gang members were responsible for at least two of the killings.

They did not immediately say whether today's shooting could be gang-related.

Estella Fajardo, 22, who was working in a store close to where the shooting happened, said she felt safe in the Mission, but then her voice trailed off.

"But you know these gangsters," she said. "They're always there."