Washington, Dec 28 (DPA) A flight from Amsterdam to Detroit requested emergency assistance beacuse of a disruptive passenger Sunday, two days after an attempted terrorist attack aboard the same flight.

The Nigerian passenger was questioned by investigators in Detroit after he reportedly spent more than an hour in the plane’s restroom, and became “verbally disruptive” when flight attendants questioned him, CNN reported. No explosives were found on the man and he deemed not to be a threat.

But the incident came amid a heightened alert after anotherNigerian man allegedly attempted to set off an explosive device on Christmas Day aboard the same flight after spending time assembling the device in the lavatory. Police removed and screened all luggage aboard the plane.

US President Barack Obama was informed of the latest incident, a White House statement said.

“The president stressed the importance of maintaining heightened security measures for all air travel,” said spokesman Bill Burton.

Umar Farouk Abdulmutallab, 23, has been charged with attempting to destroy the Northwest Airlines plane carrying 278 passengers Friday.

ABC News reported Sunday that the attack was planned by Al Qaeda in Yemen, where Abdulmutallab was trained for terrorism, and that the bomb was built there.

Al-Qaeda in the Arabian Peninsula released a written statement Sunday saying, it would seek revenge for a Dec 17 airstrike on its training camp, according to the Washington-bsed Intel Center, which monitors terrorist groups.

“We shall avenge, God willing, the blood of innocent Muslim women and children,” the statement said.

Abdulmutallab is believed to have smuggled the pentaerythritol (PETN) material on board sometime on the way from Lagos, Nigeria to Detroit via Schiphol airport in Amsterdam. He claimed he had connections to the terrorist network Al Qaeda and terrorist groups in Yemen, The New York Times reported.

The attempted attack led to heightened security at airports worldwide over the weekend.