Plane 'may have been blast target'

A major international terror alert was sparked after security staff found printer cartridges with wires attached in cargo hubs at East Midlands Airport in the UK and Dubai on Friday.

Speaking after a Cobra meeting, the UK Government's emergency planning committee to discuss the security situation, Ms May said: "The target may have been an aircraft and had it detonated the aircraft could have been brought down."

Ms May said: "I can confirm that the device was viable and could have exploded. 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. Our investigation remains sensitive. We are working closely with international partners to increase our understanding of this case and of course to bring those responsible to justice."

She continued: "At this stage there is no information to indicate another attack is imminent."

Ms May said the threat level was at "severe", meaning a terrorist attack is "highly likely" and there was no plan to change the level at this stage.

But she said: "We must take further precautionary measures. I have agreed with the Transport Secretary (Philip Hammond) that we will take immediate action to stop the movement of all unaccompanied air freight originating from Yemen into or through the UK. Direct cargo and passenger flights from the Yemen were suspended in January this year for security reasons following an earlier attempt to bomb an aircraft destined for Detroit."

She said the police and intelligence agencies were working "tirelessly" on the case.

Ms May said she had been in regular contact with Prime Minister David Cameron and briefed him following the Cobra meeting. She said: "The Government's key aim is to keep the UK safe. I will be monitoring progress and further statements will be made as necessary."