PORTSMOUTH, N.H. — A tense standoff with a passenger aboard a Boston-bound Greyhound bus ended peacefully Thursday night when the man surrendered to police, nearly 10 hours after authorities received a call that a bomb was on board.
Earlier, sixteen other adult passengers and the driver had exited the bus, which originated in Bangor, Maine, and arrived in Portsmouth for a regularly scheduled stop at about 11:20 a.m. The bus was eventually heading to New York via Boston.
Portsmouth Police Chief David Ferland said, during a press conference late Thursday night, that the local 911 dispatcher service received a call of a possible explosive on the bus, shortly after it arrived in the city.
Authorities quickly surrounded the bus, evacuated nearby buildings, including a hotel and parking garage, and closed several streets. Coming just days after a failed car bombing in New York City, the threat drew an overwhelming response, with bomb squads, SWAT teams, and a sharpshooter in an armored vehicle descending on the chaotic scene.
Ferland, who was joined by state and federal authorities at the briefing, gave few additional details about the incident. Police provided little information throughout the day.
The chief did not identify the suspect, who left the bus shortly before 9 p.m., or say if he was facing charges. He also did not reveal if a device was found. Authorities do not believe the incident was connected to terrorism, but was a local event only.
Passenger Danielle Everett, 20, of Poland, Maine, said she had no idea what was going on during the incident. When the bus arrived in Portsmouth, she said, a passenger followed the driver off the bus and said something to him. When they returned, the driver shut off the engine and told everyone to ‘‘sit tight.’’ Moments later, police cruisers surrounded the bus.
‘‘The scariest part was seeing the police cruisers surround the bus, and they all had machine guns,’’ said Everett, who was on her way to Boston, where she had planned to catch a train to Plymouth. Her possessions, and everyone else’s, were left on the bus.
The scene caused chaos in downtown Portsmouth. Police urged people to stay away from the area, and said they were operating on the premise that an explosive was on the bus.
It was not known Thursday night whether any explosive device had been discovered.
New Hampshire Governor John Lynch, the state attorney general, and the commissioner of public safety monitored the situation from the state emergency operations center in Concord, N.H.
At about 2 p.m., two-and-one-half hours after arriving in Portsmouth, passengers began leaving the bus one by one, holding their hands in the air as they walked slowly past tactical teams with guns drawn. As they disembarked, some could be seen lifting up their shirts, apparently to show they were unarmed, and being quickly surrounded by authorities. Some could be seen in handcuffs.
Everett described a dramatic scene that took place when the passengers were finally taken off the bus. She said police used a Taser to subdue a man in his 60s who refused to give his name. Once the passengers got off, they were each put in handcuffs and taken to the police station, where they were questioned individually.
‘‘I’ve never been handcuffed or had an M-16 pointed at me,’’ Everett said.
No one was injured in the standoff.
Police described the man who remained on board only as a male in camouflage pants, and would not say whether they had been in communication with him.
Everett said later that she learned from police that they were alerted because one of the passengers had heard a man sitting in the back screaming in a foreign language into a two-way radio.
The driver had disabled the bus when he was alerted to the potential threat as he pulled away from the Portsmouth stop. He parked the bus on the side of a street, between a large parking garage and a hotel, and got off the bus. Police questioned him.
It was unclear why passengers remained on board so long, although police said they had been in contact with at least some of them by cellphone before they exited.
Throughout the afternoon, police did not board the bus. Police had maneuvered a robot near the bus to take video and had also placed a device near the bus to monitor for radiation, chemical, or biological hazards. The detector did not sense anything unusual, police said.
While the standoff continued, friends and family of the passengers waited for them at the police station.
Paul Mowatt, 39, said his fiancée, Melissa Cunningham, 26, was unnerved by the ordeal.
‘‘She was pretty scared,’’ he said. ‘‘She’d been crying.’’
Ingrid Knowles, a junior from Bates College, came to meet her roommate, Megan McClelland, who was taking the bus to New York. Knowles showed a reporter a text message she had received from McClelland from inside the bus, describing police surrounding the vehicle.
‘‘Bomb scare on my bus,’’ she wrote. ‘‘Kinda scary.’’ In a later message, she said the situation was becoming more tense.
‘‘Yeah, I’m actually getting pretty scared,’’ she wrote. ‘‘Lots of guns.’’
McClelland later told a Globe reporter that passengers on the bus did not panic, even when the vehicle was surrounded by gun-wielding officers.
‘‘It was really calm,’’ she said. ‘‘Most of us were trying to assure ourselves that it was just a drill or they had seen a suspicious package. We kept saying, ‘this will be over soon.’ But when two hours rolled by, people got anxious.’’
One of the passengers, a retired New York Police officer, helped keep the peace by telling everyone that officers outside were following protocol, McClelland said.
McClelland said she also did not know about the bomb threat while she was on the bus.
‘‘I really had no idea what was going on until I left the bus,’’ she said.
McClelland said the passenger who refused to get off the bus was a thin man who appeared to be in his 40s or 50s.
Everett’s father, Dan, of Plymouth, said Danielle called him from the bus, but said she had little idea what was happening.
Dan Everett said his daughter told him the driver told passengers the bus had developed mechanical problems, and turned off the ignition and lights. A short time later, police arrived.
Greyhound spokeswoman Maureen Richmond said the bus was making a routine stop when the driver received a report of suspicious activity. He ‘‘pulled over in a safe location’’ and ‘‘ensured the passengers were safe,’’ she said. The driver has worked for Greyhound since March 2008.
Shortly before 8 p.m., passengers were released by police and boarded another Greyhound bus to Boston that was escorted from the city by an unmarked police car. Some chose to stay overnight in New Hampshire.
For residents in the vicinity, the standoff created great unease.
‘‘You hear about a bomb scare and you get anxious, you know?’’ asked Brennen Rumble, general manager of the Portsmouth Brewery on nearby Market Street. ‘‘Even though everything else seems normal — the sun’s shining, and it’s just another day in Portsmouth. But you go around this corner here, and there’s a very different situation going on.’’
Martin Finucane and John R. Ellement of the Globe Staff and Globe correspondents Ursula Munn and Stewart Bishop contributed to this report.
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