President Barack Obama has pledged his administration "will not rest" until all those behind an alleged¹ plot to bomb a US plane are brought to justice.

奥巴马总统承诺，在他执政期间，“不会停止”对密谋轰炸美国飞机的犯罪分子的追捕行动。

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This image from an extremist website purports to show Mr Abdulmutallab

In his first public comments on last Friday's incident事件，插曲, Mr Obama said he had ordered two reviews - of US terrorism databases and air travel screening.

The accused, Umar Farouk Abdulmutallab, a Nigerian, had a visa and was allowed to fly despite being on a watch-list.

Mr Obama spoke³ after it emerged a wing of al-Qaeda had claimed the plot阴谋，情节.

The US president said only the "quick and heroic actions" of passengers and crew had averted⁴转开，避免 disaster.

Call to vigilance

The 23-year-old accused, who is being held at a prison in the US state of Michigan, was restrained while allegedly trying to detonate引爆，爆炸 a high-explosive device sewn缝纫，装订 in to his underwear.

Mr Abdulmutallab is charged with attempting to blow up爆炸，炸毁 the Northwest Airlines Airbus A330 from Amsterdam, which had nearly 300 people on board, as it made its final descent to屈尊，降格 Detroit.

Mr Obama, speaking at a military base in Hawaii where he has been on holiday with his family, said: "We will not rest until we find all who were involved and hold them accountable."

Mr Obama said his administration had already taken steps to improve security, including extra air marshals空军中将 and enhanced screening at airports.

Criticism

Mr Obama said the people of America would not give in to fear, but added that its citizens should be vigilant警惕的，警醒的.

He added: "Those who would slaughter⁵ innocent men, women and children must know the United States will do more than simply strengthen our defences.

"We will continue to use every element of our national power to disrupt, to dismantle⁶拆除，解散 and defeat the violent extremists."

US Homeland Security Secretary Janet Napolitano said on Monday airport systems had failed, and that a much-criticised earlier remark of hers that security had worked was taken out of context断章取义.

Shortly before Mr Obama spoke, al-Qaeda in the Arabian Peninsula claimed responsibility for the plot.