Device 'could have exploded'
London - A suspect package from Yemen found on a US-bound cargo plane at a British airport was "viable and could have exploded", Home Secretary Theresa May said on Saturday.
Although she said Britain was not thought to be a target, she also announced a ban on all unaccompanied cargo coming from Yemen into the country.
"Our preliminary investigation is now complete. I can confirm that the device was viable and could have exploded," May told reporters following a meeting of the government's emergency committee, Cobra.
"The target may have been an aircraft and had it detonated the aircraft could have been brought down.
"We do not believe that the perpetrators of the attack would have known the location of the device when it was planned to explode."
The discovery of the British package Friday and another in Dubai caused a major international security alert and US President Barack Obama said they represented a "credible terrorist threat."
Cargo banned from Britain
May said on Saturday there were no plans to change Britain's threat level, already at its second highest level, suggesting an attack is highly likely.
But she said "further precautionary measures" were needed and said that all unaccompanied cargo from the Yemen would be banned from Britain.
"I have agreed with the transport secretary that we will take immediate action to stop the movement of all unaccompanied air freight originating from Yemen into or through the UK, and we are talking to the transport sector," the home secretary said.
Direct cargo and passenger flights from the Yemen were suspended in January after a Nigerian "underwear bomber" with links to the Arab country allegedly tried to blow up a US airliner over Detroit on Christmas Day 2009.
May said the investigation remained "sensitive" and she remained in contact with the US secretary for Homeland Security Janet Napolitano.
"We are working closely with international partners to increase our understanding of this case and of course to bring those responsible to justice," the home secretary said.