Airport security in the United States and elsewhere has been tightened since Friday when a Nigerian man allegedly tried to blow up a U.S. airliner.
The suspect, Umar Farouk Abdulmutallab, is charged with trying to detonate explosives just before Northwest Airlines Flight 253 landed in Detroit Christmas Day from Amsterdam. The material did not explode and Abdulmutallab was burned before other passengers and the flight crew restrained him.
The 23-year-old says he was trained by al-Qaida operatives in Yemen.
Abdulmutallab's family says they lost contact with him while he was studying abroad. His father, Alhaji Umar Mutallab, a prominent banker and former Nigerian government minister, had warned the U.S. embassy about his son's views.
The suspect is listed in a U.S. government intelligence database, but he was not on the "no-fly list." President Barack Obama has ordered a review of security to determine how Abdulmutallab boarded a U.S.-bound plane with potential explosives. President Obama is expected to make a statement Monday on the incident.
Prosecutors are seeking a DNA sample of the suspect, and a court hearing scheduled for Monday on that matter has been postponed.
On Sunday, authorities moved Abdulmutallab to a federal prison in Michigan from a hospital where he was treated for burns.
Homeland Security Secretary Janet Napolitano told the U.S. news network CNN there is "no indication" that the attempted attack was part of a larger terrorist plot. On Monday, she told NBC that the U.S. security system "did not work in this instance" and an "extensive review is under way."
Republican Congressman Peter King of the House Homeland Security Committee said Sunday the system failed and the suspect may have been seconds away from killing hundreds. Nearly 300 people were on the flight.
Some information for this report was provided by AP and Reuters.