The father of Umar Farouk Abdulmutallab, the 23-year-old charged with attempting to bomb a US passenger plane en route to Detroit from Amsterdam, says he informed the US embassy in Nigeria as well as the Nigerian Intelligence Agency of his son's extremist views.

According to a cousin of Abdulmutallab, Abdulmutallab's father Umaru Mutallab offered approval for his son's desire to study Arabic in Yemen over the summer. Prior to the trip, Abdulmutallab had a good reputation among relatives as "a very religious, polite and studious fellow."

However, Mutallab and other members of the family became worried when Abdulmutallab said he was dropping his post-graduate program in business administration and was pursuing another course in Yemen which he did not disclose.

Mutallab finally decided to tell authorities about his son when Abdulmutallab sent a text message informing his family that he was severing all contact. Upon hearing of his attempted attack, Abdulmutallab's family said they were completely stunned.

"He was such a brilliant boy and nobody in the family had the slightest thought he could do something as insane as this," one relative told AFP.

Reported links to al-Qaeda

As the case against Abdulmutallab builds, there was speculation that the 23-year-old had ties to al-Qaeda in Yemen. Abdulmutallab allegedly told investigators that he acquired his explosives, and instructions on how to use them, from the terrorist group's operatives there.

However, US Homeland Security Secretary Janet Napolitano warned it would be "inappropriate" to speculate his links to al-Qaeda, since the investigation is ongoing.

A US official said Abdulmutallab was entered into an intelligence database of known and suspected terrorists last month, but added that there was not enough data on him at the time to put him on a "no-fly" list.

A "sophisticated" device

Families and friends faced an anxious wait

Abdulmutallab's suspected explosive device has been described as "fairly sophisticated" and included a powdered substance located in his underwear, as well as liquid contained in a syringe.

An initial FBI analysis revealed traces of one of the same substances used by the so-called "shoe bomber," Richard Reid, in his failed attempt to blow up a US passenger jet days before Christmas in 2001.

Referring to the latest incident, US Attorney General Eric Holder said in a statement that had "this alleged plot to destroy an airplane been successful, scores of innocent people would have been killed or injured."

Abdulmutallab was overpowered by other passengers after they heard a pop and saw flames as the plane made its approach to land. Two passengers were injured and the suspect suffered serious burns. Airline officials described the explosives as resembling firecrackers.

The fire was put out with blankets and fire extinguishers and the man was dragged to the front of the plane. The Northwest Airlines flight, operated by Delta, made a safe landing and all 278 passengers were escorted to safety.

EU examines its end

Amsterdam's Schiphol airport will need to review its security procedures

The US has called on airlines and airports worldwide to implement tighter security measures, including frisks for all passengers headed to the US, and extra checks for carry-on luggage.

Authorities in London have been searching buildings where Abdulmutallab was believed to have stayed while studying engineering there.

"We are in liaison with the US authorities and searches in London are being conducted as part of ongoing enquiries," a police spokeswoman in the British capital said.

The European Commission said on Saturday that it was investigating whether proper security measures had been followed at Amsterdam's Schiphol airport, where the Delta flight originated.

"I am horrified by the attempted terrorist attack," Jacques Barrot, vice president of the Commission said in a statement. "The European Commission is in contact with the relevant authorities to make sure that all rules and procedures were followed in Europe. We are in touch with our Dutch and US counterparts."

Dutch counter-terrorism authorities said Abdulmutallab transited at Schiphol after arriving on a KLM flight from Lagos, Nigeria. Although he went through a security checkpoint at Schiphol, transit passengers generally face looser checks than other departure passengers.

mk/AFP/AP/dpa/Reuters

Editor: Andreas Illmer