SAN'A, Yemen: Officials in Yemen are investigating whether the Nigerian suspected in the attempted Christmas Day attack on a US airliner spent time with Al-Qaida militants in the country in the months leading up to the botched bombing.

Administrators, teachers and fellow students at the San'a Institute for the Arabic Language, where Umar Farouk Abdulmutallab had enrolled to study Arabic, told reporters on Tuesday that he attended school for only the month of Ramadan, which began in late August. That has raised questions about what he did during the rest of his stay, which continued into December.

Abdulmutallab, 23, told US officials after his arrest he received training and instructions from Al-Qaida operatives in Yemen, a law enforcement official has said.