2 killed, 4 arrested in San Francisco homicides 2 hours apart

San Francisco police are investigating separate stabbings over the weekend in the Mission District and Chinatown that left two men wounded, including one with life-threatening injuries. San Francisco police are investigating separate stabbings over the weekend in the Mission District and Chinatown that left two men wounded, including one with life-threatening injuries. Photo: Spencer Platt / Getty Image, Getty Image Photo: Spencer Platt / Getty Image, Getty Image Image 1 of / 28 Caption Close 2 killed, 4 arrested in San Francisco homicides 2 hours apart 1 / 28 Back to Gallery

A woman and a man were killed two hours apart late Thursday in San Francisco, becoming the second and third homicides in the city in two days, police said.

Police responded to the first slaying just before 9:30 p.m. in lower Pacific Heights. A 56-year-old woman was found stabbed to death on the 2000 block of Sutter Street near Fillmore Street, police said.

Officials arrested a 39-year-old man in the case but did not release his name or other details.

Later Thursday, a man in his early 20s along with an 18-year-old woman were shot near Mission Street and Geneva Avenue on the edge of the Excelsior district. The man died, but the teenager was expected to survive, police said.

Officers arrested two teenage girls, ages 17 and 18, along with a 20-year-old man. Police did not provide further details.

“They’re still both fresh and the reports are still being done,” Officer Giselle Talkoff, a police spokeswoman, said Friday morning.

The Thursday night killings came a day after a 21-year-old woman was shot to death in the Mission District. The medical examiner’s office identified her Friday as Lisa Williams. Officials said her city of residence was unknown.

No arrests have been made in that case.

Kimberly Veklerov is a San Francisco Chronicle staff writer. Email: kveklerov@sfchronicle.com Twitter: @kveklerov