NEW YORK — Police found a car bomb in a parked sport utility vehicle Saturday evening in New York City’s Times Square, then evacuated buildings and cleared streets of thousands of tourists in the landmark known as the “Crossroads of the World.”

A mounted police officer noticed smoke coming from the SUV at 6:30 p.m., police said. Bomb investigators found propane tanks, powder and an apparent timing device inside, according to a law enforcement official who wasn’t authorized to release the information and spoke on condition of anonymity.

Police evacuated several residential and commercial buildings and cleared the streets of people. Police were deployed around the area with heavy weapons on empty streets in the heart of midtown Manhattan that normally teem with thousands of theatergoers and tourists.

Some tourists reported hearing a small explosion hours after the car was first located.

Shelly Carlisle, of Portland, Ore., said police crowded into her Broadway theater after the curtain closed on “Next to Normal,” a show on the same block where the SUV was found.

“At the end of the show, the police came in. We were told we had to leave,” Carlisle said. “They said there was a bomb scare.”

The car was parked on 45th Street, and the block was closed between Seventh and Eighth avenues as a precaution, police said. Times Square lies about four traffic-choked miles north of the site where terrorists bombed the World Trade Center in 1993, then laid waste to it on Sept. 11, 2001.

FBI agents are on the scene with the New York Police Department, and the matter is being taken seriously, said Paul Bresson, head of the FBI’s public affairs office at bureau headquarters in Washington.

The Homeland Security Department is aware of the situation, but the NYPD has it under control and is investigating, said a Homeland Security official who spoke on condition of anonymity because the investigation is in progress.

The block that was closed is one of the prime blocks for Broadway shows, with seven theaters housing such big shows as “Billy Elliot” and “Lend Me a Tenor.”

The curtain at “God of Carnage” and “Red” opened a half hour later than usual, but the shows were not canceled, said spokesman Adrian Bryan-Brown.

Katy Neubauer, 46, and Becca Saunders, 39, of Milwaukee, were shopping for souvenirs two blocks south of the SUV when they saw panicked crowds.

“It was a mass of people running away from the scene,” Neubauer said.

Said Saunders: “There were too many people, too many cops. I’ve never seen anything like it.”

In December, a van without license plates parked in Times Square led police to block off part of the area for about two hours. A police robot examined the vehicle, and clothes, racks and scarves were found inside.

Contributing to this report were AP Washington bureau chief Ron Fournier, and Associated Press writers Eileen Sullivan and Pete Yost in Washington and Michael Kuchwara in New York.