Failure to find airport bomb 'a weakness', expert says
The initial failure to find the bomb on a plane at East Midlands airport was a "weakness", the independent reviewer of counter-terrorism laws has said.
Lord Carlile said technical equipment needed to be investigated to ensure it was "absolutely up to date".
Home Secretary Theresa May has said the "crucial thing" was that the bomb - on a cargo plane - had been found.
The government's emergency planning committee, Cobra, will meet on Monday to discuss increasing cargo security.
Mrs May has pledged to review air freight security, but the BBC's political correspondent Iain Watson says he is unaware of any launch of a new or wider review of airport security other than the need for increased vigilance.
A Metropolitan Police spokesman said UK investigators had at first declared the device at East Midlands "safe" before carrying out a re-examination as a "precaution".
"Further examination of the package by explosives officers identified items of concern.
"Cordons were put back in place as a precaution prior to items being removed for further scientific analysis," he said.
A female student arrested in Yemen on suspicion of posting the bomb - and another discovered in Dubai - has now been freed, relatives are quoted as saying.
Meanwhile, US officials have said a Saudi-born bomb-maker, Ibrahim Hassan al-Asiri, is the prime suspect for constructing the devices, which were placed on US-bound flights.
Lord Carlile told the BBC: "The one weakness I would identify from what we must regard as a success in recent days is that the technical equipment used at East Midlands Airport apparently did not detect the explosives at the first attempt.
"So we must have a look at the technology to ensure that it's absolutely up to date."
He said it would be unfeasible to check each of the thousands of parcels that fly in and out of UK airports but explosives sniffer dogs should used more extensively.
"The use of intelligence and good policing experience is the most important aspect of this," he added.
Keith Vaz MP, who chairs the All Party Yemen Group, said: "We need to make sure that the equipment for the searching of passengers and freight ought to be given to Yemen. That is what they have been asking for for a number of years."
Earlier, speaking on the BBC One's Andrew Marr Show, Mrs May said: "Certainly, we have to look at our processes of searching and how we detect these devices.
"The crucial thing is we did find it and we were able to take action on it.
"What we have done is taken action in relation to future unaccompanied freight from the Yemen which would either be coming into the UK or through the UK, and banned that freight."
The home secretary said it could not be determined if the bombers had planned to blow up the planes over the UK or US.
She said: "As I understand it, with these freight flights, sometimes the routing can change at the last minute so it is difficult for those who are planning the detonation to know exactly where the aircraft would be."
She stressed that they were engaged in a "constant battle" with terrorists and said physical security was only one element of the UK's defences alongside intelligence and police work.
A spokesman for Qatar Airways said the parcel found in Dubai travelled on two separate passenger planes via the airline's hub in Doha.
Mr Cameron said the device found at East Midlands airport was designed to go off on the aircraft.
A Downing Street spokesman said Mr Cameron discussed the attempted terrorist plot with German Chancellor Angela Merkel, who is on a two-day visit to the UK, and both pledged to maintain their "close and effective" counter-terrorism co-operation.
The British International Freight Association said there should be a review of all aspects of air cargo following the incident at East Midlands airport on Friday.
Director general Peter Quantrill told the BBC: "The issue requires attention to look at systems and procedures - though it must be stressed that there are already well established, in depth and organised processes there.
"It was a very serious issue but it would be wrong to suggest that air freight security is not treated in the same way as passengers when it comes to security."
The woman arrested in Yemen has been named by human rights groups as Hanan al-Samawi, 22.
The authorities initially described her as a medical student, but later reports said she was studying computer engineering at the University of Sanaa and had no known links to Islamist militants.
Dubai and UK officials say the bombs had the hallmarks of al-Qaeda.
The two packages were addressed to synagogues in the Chicago area. Both bombs were apparently inserted in printer cartridges.