Flights from Heathrow Terminal 3 were suspended over a 'security issue.'
The incident has sparked travel chaos for passengers as police were summoned to the terminal.
Twitter users are saying there are roughly 1,500 people waiting to be screened, while also saying there has been a lack of information about the incident.
The Sun is claiming the security alert was caused by a 'suspicious package'.
In responding to customers, Heathrow Airport has released the following statement by Twitter:
Pictures on Twitter show long queues in the terminal:
The Metropolitan Police released this statement on Twitter:
More information to follow.