Obama set to tighten air security

US President Barack Obama is set to announce tightened airline security, after his officials update him on reviews prompted by a plane bomb plot.

Reviews of airport screening and of the US watch-list system were ordered after a Nigerian man known to US officials allegedly got on a plane with a device.

He tried to blow up the plane on 25 December as it prepared to land in the US city of Detroit, investigators say.

It has prompted changes to airport screening around the world.

Fourteen countries, including Nigeria, Somalia and Yemen, have been singled out by Washington for enhanced security measures for travellers.

On Tuesday at the White House, President Obama is expected to outline steps to improve watch-lists and deter future attacks, after his meeting with about 20 security and intelligence officials.

Prosecution investigation

Secretary of State Hillary Clinton, Defence Secretary Robert Gates, Homeland Security Secretary Janet Napolitano, CIA Director Leon Panetta and FBI Director Robert Mueller are among those expected at the meeting, the Associated Press news agency reported.

Mr Obama will be updated on the investigation focusing on Umar Farouk Abdulmutallab, the 23-year-old Nigerian who remains in custody, charged with attempting to destroy a plane.

Mr Abdulmutallab began his journey in Lagos, Nigeria, and changed planes at Schiphol airport in Amsterdam, the Netherlands.

His name was in a US database of about 550,000 suspected terrorists, but was not on a list that would have subjected him to additional security screening or kept him from boarding the flight.

Since the incident, officials have moved dozens of names on to "watch-" and "no-fly" lists, as they seek to overhaul security, White House spokesman Bill Burton said earlier.

Watch-list update

Those on the watch-list are subject to extra security checks, while those on the no-fly list are not allowed to board flights to the US.

Yemen-based al-Qaeda in the Arabian Peninsula said last week it had trained and equipped Mr Abdulmutallab for the plane plot.

The US re-opened its embassy in Yemen on Tuesday, following what it called successful counter-terrorism operations by government security forces on Monday north of the capital.

A BBC correspondent in the Yemeni capital Sanaa says the embassy was referring to a strike that reportedly killed two al-Qaeda operatives.

The embassy had closed on Sunday in response to what it said were al-Qaeda threats. The British and French embassies have resumed operations, but remain closed to the public.

Yemeni authorities have tightened security measures at Sanaa's airport, as well as around several other embassies.

Obama orders air security review after jet bomb attempt

US President Barack Obama has ordered a review of air security measures after a Nigerian man allegedly tried to blow up a trans-Atlantic jet on Christmas Day.

Spokesman Robert Gibbs said the president wanted to know how a man carrying dangerous substance PETN had managed to board a flight in Amsterdam.

He said the system of watch-lists would also be examined after it emerged the man was listed and known to officials.

A US record for 23-year-old Umar Farouk Abdulmutallab was created last month.

Mr Gibbs told ABC News that the review would examine, firstly, the system of watch-lists used by government agencies, which includes three lists which become progressively shorter as risk increases.

'Dangerous substance'

The lists include a watch-list, with some 550,000 names on it, a "selectee" list with 18,000 people within the higher-risk category, and a "no-fly" list with 4,000 names of people who are not permitted to board planes.

Mr Abdulmutallab was placed on the lowest-risk list by US authorities in November 2009, after his father alerted authorities about the behaviour of his son.

Mr Gibbs said the number of people on the watch-list was "a huge number".

"The president has asked that a review be undertaken to ensure that any information gets to where it needs to go, to the people making the decisions. The president wants to review some of these procedures and see if they need to be updated," he said.

On 24 December Mr Abdulmutallab travelled from Nigeria to Amsterdam and then on to Detroit with an explosive device attached to his body, US officials say.

Shortly before the flight was due to land in the US, he allegedly attempted to detonate the device beneath a blanket but he was overpowered by passengers and crew.

Mr Abdulmutallab, the son of a prominent Nigerian banker, has been charged by US authorities with trying to blow up the Northwest Airlines flight as it was coming in to land.

US airlines especially have tightened security after the attempt, increasing screenings and body searches and, in some cases, confining passengers to their seats without pillows or blankets for the last hour of their flight.

Mitigation measures

Mr Gibbs said "air detection capabilities" would also be examined as part of the review.

"The president has asked the Department of Homeland Security to answer the - quite frankly - the very real question about how somebody with something as dangerous as PETN could have gotten onto a plane in Amsterdam."

PETN, or pentaerythritol, is the same material used by convicted shoe bomber Richard Reid who tried to destroy a trans-Atlantic flight in 2001.

Mr Abdulmutallab's route originally began in Yemen, from where he travelled to Ethiopia, then to Ghana and finally Nigeria.

According to Nigeria's information minister, Mr Abdulmutallab had arrived and flown out of Nigeria in the space of a single day.

"The man in question has been living outside the country for a while," said Dora Akunyili.

"He sneaked into Nigeria on the 24th of December and left the same day."

Nigerian authorities, who on Sunday pledged to co-operate fully with the US investigation, said screening would be enforced for all passengers passing through the country's 22 airports.

Wealthy or influential people and their families are often allowed to skip checks, media reports say.

Speaking to ABC News, Homeland Security Secretary Janet Napolitano said there was no immediate indication that Mr Abdulmutallab was part of a broader terror plot.

"Right now we have no indication that it is part of anything larger. But obviously the investigation continues. And we have instituted more screening and what we call mitigation measures at airports," she said.