LONDON—London's Heathrow airport reopened a busy international terminal on Tuesday after a security scare led to the cancellation of around 55 flights.
Thousands of passengers were evacuated from Terminal 4 after a suspect bag was found shortly before midday (1100 GMT), the airport's operator BAA, a unit of Spanish infrastructure and construction company Grupo Ferrovial, said.
Police also ordered the evacuation of the departure lounge so that all passengers could be searched a second time.
The terminal reopened shortly after 5 p.m.
Flights arriving at the terminal, which handles only international flights, were not affected.
British Airways said it had cancelled all its European departures from the terminal for the day, as well as all long-haul flights due to depart between 3 p.m. and 9 p.m. (1400 and 2000 GMT).
An airport spokesman said passengers due to fly from the terminal on Tuesday evening should check their flight with their airline.
Britain's security threat level has been set at "critical" since two car bombs were found in central London on Friday and members of a suspected al-Qaeda cell attacked an airport in Scotland on Saturday.
Eight suspects have been arrested in Britain and Australia.
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