RAF Typhoon jets have been launched to investigate an incident involving a civilian aircraft within UK airspace, the Ministry of Defence has said.
A Pakistan International Airlines plane has been diverted from Manchester to Stansted Airport, a Manchester Airport spokesman said.
An Essex Police spokeswoman added: “An incident has occurred on an aircraft. Police and partners are responding.”
The BBC understands that the plane has now landed in Stansted.
BBC defence correspondent Jonathan Beale said that police were expected to meet the plane at the airport.
The plane, flight number PK709, reportedly left Lahore at 09:35 local time. It was due in at Manchester at 14:00 BST.
Read more: BBC News