The passenger at the center of a daylong bomb scare on a bus was a foreign national from Africa who was too scared to get off the bus, a person with knowledge of the investigation told The Associated Press on Friday.The person, who spoke to the AP on condition of anonymity because he was not authorized to speak publicly, said the bomb scare was sparked by another passenger who called police believing a non-English-speaking rider had mentioned a bomb.The emergency call around 11:15 a.m. Thursday prompted authorities to evacuate buildings and streets in Portsmouth and to surround the bus with a bomb squad and sharpshooters. The other 16 passengers and the driver got off safely, but the non-English-speaking man refused to leave until about 8:40 p.m.He emerged from the bus shirtless and in camouflage pants, with his hands held high over his head. He then went to his knees before soon getting up and appearing to follow orders from police to walk away from the bus.He was taken into custody and was being questioned, but the case is not terrorism-related, Portsmouth Police Chief David Ferland said at a late-night news conference during which he refused to answer questions. US Attorney John Kacavas said the passenger was from Africa.The person familiar with the investigation said the passenger is unlikely to face criminal charges. No explosives were found on the bus, which began its trip in Bangor, Maine, made a scheduled stop in Portsmouth and was en route to Boston and then New York.More information was expected to be released at a midday news conference.Several federal agencies had responded to the scene. US Immigration and Customs Enforcement spokesman Harold Ort said only that there was an "ongoing issue" and that ICE was helping the investigation.Throughout the day, police kept the curious at a distance and gave little information of what was happening. They said they established a way to communicate with the remaining passenger but wouldn't give details.Passenger Danielle Everett, 20, said she didn't see anything suspicious on the bus."It really wasn't any big deal," said Everett, who was met at the Portsmouth police station by her concerned father.