Under Yemen's rules, Abdulmutallab should have been stopped and not allowed on the plane when he left Yemen because he overstayed the visa, Yemeni security officials told The Associated Press today.
Administrators at the school where Abdulmutallab studied believed he had left the country in September, they said.
"We arranged a taxi to take him to the airport on Sept. 21 and we said goodbye," school director Muhammad al-Anisi told the AP. "Our responsibility toward him ended that day."
Al-Anisi said no one from the airport security or immigration had subsequently contacted the school to ask about the student's whereabouts.
The officials said Abdulmutallab left Yemen Dec. 7 on a flight to Ethiopia and then continued on a few days later to Ghana. In Ghana's Accra Airport Dec. 16, he purchased his $2,853 plane ticket with cash, what has been considered a red flag for potential terrorists.
A Nigerian government official says that Abdulmuttallab traveled by road on a well-known route from Accra to Lagos frequently traveled by dissidents. The source says the Nigerian government is still getting information on exactly how long he was in Lagos, but information indicates that he spent no more than "48 hours."
But the Nigerian government put out a statement today that said Abdulmutallab flew into Lagos from Ghana and only spent 30 minutes in Lagos as he switched planes.
At Lagos airport, Abdulmutallab boarded the intercontinental flight without luggage, another red flag for potential terrorists.
Critics have also questioned why the U.S. did not revoke Abdulmutallab's visa after Britain refused to grant him a visa earlier this year. Britain rejected the request because Abdulmutallab applied to study at a nonexisting college.
The State Department said today, "We understand that the U.K. denial of a visa to Abdulmutallab was a routine decision based on his application to pursue academic study at a U.K. institution not being credible. The denial was not based on terrorist grounds or other security concerns. U.K. authorities did not inform us that they denied a student visa for Abdulmutallab."