Cargo aircraft have been grounded at Newark and Philadelphia airports as US authorities investigate suspicious packages.

The jets are being examined by the Transport Security Administration.

According to CNN, US airports have been on alert since a package was discovered on a UPS flight to Chicago from Yemen last night. The aircraft was at a London airport when the alarm was raised.

Reuters has reported that a suspicious package was found at East Midlands airport today, and is currently being examined by police. Authorities have not linked the East Midlands incident to the discoveries in London or the US, and the airport is operating as normal.