An armed man hijacked a U.S.-bound Greyhound bus near Montreal Friday, forced the driver to take him to Ottawa and held several hostages at gunpoint outside Parliament for six hours, then surrendered to the Royal Canadian Mounted Police.

The unidentified gunman surrendered peacefully about 8 p.m. EDT after releasing the driver and the last of about 10 passengers on the bus when he seized control around noon EDT. No one was injured, police said.An elderly passenger who was released when the hijacking began said the gunman claimed to have explosives and threatened to blow up the bus, police said. The Canadian Broadcasting Corp. and the CTV broadcast network said he demanded the release of political prisoners in Lebanon.

After bordering the New York-bound bus in Montreal, the gunman seized control of the vehicle at Champlain Bridge outside the city and ordered the driver to head toward Ottawa. Once in the capital, he ordered the driver to park the "Americruiser" bus on the front lawn of Parliament.

The gunman released several hostages at intervals during the afternoon. Besides the elderly man released on the Champlain Bridge, two hostages, a man and a woman, left the bus shortly after arriving at Parliament Hill. A young woman was released three hours later and a fifth, a woman, walked off later.

Police and witnesses said the gunman, who spoke French, fired at least three shots outside Parliament, sending passersby scurrying for cover but injuring no one.

"As we were walking down, a man leaned over the bus driver and shot his gun at our feet," said Lorean Lapointe of Eureka, Calif., who was visiting the Parliament buildings. "He fired another shot, so we ran back."

Lapointe had watched the departure of Costa Rican President Oscar Arias from the Parliament buildings moments before the bus arrived on Parliament Hill, near the U.S. Embassy, at about 2 p.m. EDT.

RCMP sniper units and paramilitary teams immediately surrounded the Parliament buildings,which are across the street from the U.S. Embassy, and a police van could be seen parked immediately behind the commandeered vehicle.