Diners at a crowded Greenwich Village restaurant were left scrambling for air after an unidentified man threw a grenade-sized smoke bomb into the building, leaving patrons, including "Planet Terror" actress Rose McGowan, to be suffocated in thick red smoke, NYPD authorities said. With no injuries being reported, Bar Pitti was aired out and re-opened before 9 p.m. Friday, according to workers.

The prankster popped out from an underground subway service grate outside of Bar Pitti on Sixth Avenue between Bleecker and Houston at about 5:30 p.m. and hurled the explosive into the outdoor patio area of the restaurant before fleeing back through the grate, which led to the subway system, police said.

One witness said the smoke bomb resembled a red safety flare when it blew up, New York Daily News reported.

"It was a big one...about the size of a grenade," said one restaurant employee, who wished to remain anonymous. "Everybody panicked and half the people ran out. I'm just glad it wasn't anything explosive."

"We were just trying to relax and have a nice dinner, and then there was smoke and a bunch of policemen," said Sara Bond, who was visiting from New Orleans.

It was "quite a big commotion," said Australian tourist Tine Millet. "I've seen everything in New York, absolutely everything."

"Someone just threw two red smoke bombs into the restaurant I was eating in," McGowan tweeted about the explosion. "Eyes are burning. #NYCWHAT."

Her friend's 4-year-old son had been briefly "lost in the smoke," the actress told the website Gossip Cop, adding that she "thought it was a (real) bomb."

Following the incident, security measures at the city's subway station were questioned since the man probably had to walk through tunnels to get to the service entrance, with neighbor Monica Vickers wondering if the explosion had been terror-related, according to NBC News.

"I guess they're going to have to do more security or something, right?" she said.

But police did not comment on how they believed the man to have slipped underground and up through the grate.

Meanwhile, the suspect was described as a man in his 30s with blonde hair, wearing a baseball cap and a T-shirt with an American flag on it. He remains at large since Friday night, according to police.