currently saying on
cnn.com:
Meanwhile, heightened security measures were in place at London's Heathrow Airport on Tuesday following the discovery of a suspicious bag.
...
Travelers at Heathrow were warned to expect delays as authorities introduced measures including "secondary searches" of departing passengers in response to the discovery of the suspicious bag at the airport's Terminal 4.
"Contingency plans have now been activated to ensure that we are able to effectively manage the increase in resource that this secondary search requires," the British Aviation Authority said in a statement. "We are working with the police to bring a swift resolution to the incident."