Man detained after reports of gun drawn at Metreon theater in SF

Police detained a man while evacuating the Metreon theaters in downtown San Francisco after receiving reports of a man armed with a handgun Tuesday night.

A man pulled a gun inside Theater 10 after an altercation about 7:30 p.m., witnesses said.

The man was yelling and behaving erratically just as the previews wrapped up before a showing of “Allied,” said a witness, who identified himself as Gary.

An SFPD officer gives a pedestrian instructions on how to get his car out of the 5th and Mission Garage as San Francisco Police investigated reports of a man brandishing a gun in a theater at the Metreon in San Francisco, Calif., on Tuesday, November 29, 2016. less An SFPD officer gives a pedestrian instructions on how to get his car out of the 5th and Mission Garage as San Francisco Police investigated reports of a man brandishing a gun in a theater at the Metreon in San ... more Photo: Carlos Avila Gonzalez, The Chronicle Buy photo Photo: Carlos Avila Gonzalez, The Chronicle Image 1 of / 14 Caption Close Man detained after reports of gun drawn at Metreon theater in SF 1 / 14 Back to Gallery

Gary said he went to confront the man, who was sitting in the four rows closest to the screen, and when the man wouldn’t quiet down, Gary said he left to get a manager.

When he returned, Gary said, people were screaming and running out of the theater.

Though the theater was dark, witness Jeff Wincek said he saw the glint of a gun barrel and that “it was definitely a pistol” that the man was waving.

After he pulled the gun, the man stayed seated as others ran out, Wincek said.

“He didn’t stand up, he didn’t make a big scene,” he said. “He was watching the movie start and he wasn’t in any hurry and that was pretty alarming.”

Police received a 911 call about a possibly armed man at 7:55 p.m., said Officer Grace Gatpandan, police spokeswoman. Officers evacuated the theater in an abundance of caution, and the Police Department’s SWAT team responded to the scene, she said.

One person was located and detained, and officers were able to find a handgun, Gatpandan said.

An investigation is ongoing, and authorities will not be releasing the man’s name Tuesday, Gatpandan said.

No injuries were reported, but members of the public were asked to avoid the area of Mission between Third and Fourth streets while the investigation was still under way.

Michael Bodley and Vivian Ho are San Francisco Chronicle staff writers. Email: mbodley@sfchronicle.com vho@sfchronicle.com Twitter: @michael_bodley @VivianHo