The San Francisco Police Department is seeking an unknown shooter or shooters Thursday, after early-morning gunfire in the Tenderloin killed one man and injured three others.

Details remain scarce, but here's what we do know: At 1 a.m. Thursday, police say that three men and one woman were shot near the intersection of Ellis and Jones Streets.

As of publication time, police didn't have any suspect information to release, saying only that the suspect was "unknown" and used a handgun in the crime.

A 59-year-old man, a 49-year-old woman, and a 53-year-old man were injured in the attack, and were all transported to San Francisco General Hospital with injuries that police say are not life-threatening.

A fourth victim, a man of as-yet unknown age, was struck in the torso by at least one shot. Though he was transported to the hospital for treatment, he was pronounced dead on arrival. As of publication time, he had not been publicly identified by the San Francisco Medical Examiner's office.

This is San Francisco's 34th homicide of 2016, following the shooting death Saturday of 19-year-old Alejandro Valle. Three suspects are being sought in his slaying, but as of Thursday no arrests have been made.

Citing the ongoing investigation, police declined to provide further details regarding today's incident. They did confirm, however, that no arrests had been made in the case, and that the suspect or suspects remain at large.