London:
British Home Secretary Theresa May has said that authorities are probing whether a US-bound package from Yemen containing explosives was a "viable" bomb.
"At this stage I can say that the device did contain explosive material. But it is not yet clear that it was a viable explosive device. The forensic work continues," she said.
Earlier, two mail bombs sent from Yemen to synagogues in Chicago unleashed fears of a renewed Al-Qaida terror offensive against the US and European nations.
President Barack Obama termed it as a "credible terrorist threat".
"At this stage there is nothing to suggest that any location in the UK was being targeted. We are urgently considering what steps need to be put in place regarding security of freight originating from Yemen. For security reasons there are currently no direct flights from Yemen to the UK," she said.
May said she had spoken with US Secretary for Homeland Security Janet Napolitano.
She said the British government's emergency planning committee, known as COBRA, had a meeting on Friday and would meet again on Saturday.
The Home Secretary said: "Safety and security of the UK remains my number one priority. We are working closely with our international colleagues and will continue to do so."
Britain suspended direct flights from Yemen 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 in 2009.
British police said a suspect package had arrived aboard an "America-registered cargo plane" at East Midlands Airport during a "routine stopover".
The plane was en route to Chicago via Philadelphia. Police said "explosives officers" attended the airport but the airport "continued to operate as normal during the day."