Police in the US found an "amateurish" but potentially powerful bomb in a smoking sport utility vehicle in New York's Times Square, then cleared the streets of thousands of tourists milling through the landmark district so they could dismantle it, authorities said today.
"We avoided what we could have been a very deadly event," Mayor Michael Bloomberg said. "It certainly could have exploded and had a pretty big fire and a decent amount of explosive impact."
Investigators removed three propane tanks, consumer-grade fireworks, two filled five-gallon petrol containers, and two clocks with batteries, electrical wire and other components, Police Commissioner Raymond Kelly said at a news conference early today. A black metal box resembling a gun locker was also recovered.
"I think the intent was to cause a significant ball of fire," Mr Kelly said.
Mr Bloomberg called the explosive device "amateurish" but potentially deadly, noting: "We are very lucky."
A white robotic police arm broke windows of the black Nissan Pathfinder sport utility vehicle to remove any explosive materials after a T-shirt vendor alerted police to the smoking vehicle at about 6:30pm (11.30 pm BST) yesterday.
Heavily armed police and emergency vehicles shut down the city's busiest streets, teeming with taxis and theatregoers on one of the first summer-like days of the year.
A Connecticut licence plate on the vehicle did not match up with its owner, according to authorities, who did not know a motive. Police interviewed the Connecticut car owner, who told police he had sent the plates to a nearby junkyard, Mr Bloomberg said. Police are reviewing surveillance video and looking for more.
After the vendor noticed smoke coming from the SUV, police cleared buildings and streets at the so-called "Crossroads of the World"; the area remained closed hours later. Officers were deployed around the area with heavy weapons on empty streets in the heart of busy midtown Manhattan.
Shelly Carlisle, of Portland, Oregon, said police crowded into a Broadway theatre 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," Ms 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 where terrorists bombed the World Trade Centre in 1993, then laid waste to it on September 11, 2001.
The block that was closed is one of the prime blocks for Broadway shows, with seven theatres 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 cancelled, 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," Ms Neubauer said.
Said Ms Saunders: "There were too many people, too many cops. I've never seen anything like it."
Mayor Michael Bloomberg left early from the White House correspondent's dinner on Saturday night.
President Barack Obama, who attended the annual gala, praised the quick response by the New York Police Department, White House spokesman Nick Shapiro said. He has also directed his homeland security and counterterrorism adviser, John Brennan, to advise New York officials that the federal government is prepared to provide support.
Brennan and others will keep Mr Obama up to date on the investigation, Mr Shapiro said.
The FBI Joint Terrorism Task Force in New York responded along with the NYPD, said agent Richard Kolko.
Authorities had no suspects and no motive early today in the latest threat to New York, where a Colorado man recently pleaded guilty to plotting an attack on the subway system to coincide with the eighth anniversary of September 11.
Officials said the device found on Saturday was crudely constructed, but Islamic militants have used propane and compressed gas for years to enhance the force of explosives. Those instances include the 1983 suicide attack on the US Marines barracks at the Beirut airport that killed 241 US service members, and the 2007 attack on the international airport in Glasgow, Scotland.
In 2007 the US military announced that an al Qaida front group was using propane to rig car bombs in Iraq.
Times Square has been a frequent target, if not for potential terrorists, then for rabble-rousers.
In December, a van without licence 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.
In March 2008, a hooded bicyclist hurled an explosive device at a military recruiting centre in the heart of Times Square, producing a flash, smoke and full-scale emergency response. No suspect was ever identified.
In December, police evacuated thousands of holiday tourists from Times Square after finding a white van that had been parked there for days without licence plates and blacked-out windows. No bombs were found, and police later said they overlooked the van because it contained a parking placard for a non-profit police group.
Police have spent years trying to crack down on street hustlers and peddlers preying on tourists. But there have been two major gunfights in recent months. A street hustler armed with a machine pistol exchanged shots in December, shattering a Broadway theatre ticket window, before police fatally shot the man.
Four separate instances of shootings and more than 50 arrests on a mile-long stretch of Manhattan last month around Times Square prompted the mayor to call the mayhem "wilding".