A San Francisco police officer was struck and injured by a vehicle on Turk Street between Franklin Street and Van Ness Avenue Wednesday afternoon, and the extent of the officer's injuries are not yet known.

ABC 7 was reporting from the scene, and the officer, who was on bike patrol at the time, was transported to the hospital with extremely serious injuries. The Chronicle reports that his condition was critical as of 3 p.m. and he was headed into surgery.

The incident happened at 12:21 p.m., according to CBS 5, when a white Lexus SUV reportedly was responsible for the hit-and-run.

A large police presence then gathered around Buena Vista Park, and the SFPD put out a notice on Twitter for those in the area to shelter in place — as CBS 5 reports, this is due to the fact that the suspect vehicle was found parked near there, and the suspect reportedly then ran off, possibly toward Golden Gate Park.

SFPD spokesperson Sgt. Michael Andraychak gave a press conference this afternoon, and as the Chronicle reports he says the Tenderloin Station officer was "investigating a firearms case when the suspect in that case saw him approach and hit him with a tan or gold sport utility vehicle." The photo below, and CBS 5's earlier report, suggest that the vehicle is white, not gold, but this case is still unfolding.

Apparently, the suspect has not yet been apprehended.

This story has been updated throughout.