The Prime Minister said investigators believe they were involved in the incident Burnham told British broadcasters on Wednesday that British and American officials are carrying out a "complex and serious" investigation into how five men and three vans came to be near the perimeter of RAF Fairford. Key points and original sources are listed below.

• The Prime Minister said investigators believe they were involved in the incidentS1

• Burnham told British broadcasters on Wednesday that British and American officials are carrying out a "complex and serious" investigation into how five men and three vans came to be near the perimeter of RAF Fairford.S2

• Five British nationals, all in their mid-20s, were bailed under investigation on MondayS3

• The UK is working closely with US and the authorities have the situation under ‘the strongest grip’, the Prime Minister insisted.S4

• PM also defends decision to release suspects on bail and expresses ‘complete confidence’ in security servicesThere are “strong indications” that Iran played a role in events in which five men were arrested near RAF Fairford in Gloucestershire as part of a terr...S5

• The Prime Minister said investigators believe foreign actors were involved at the incident near RAF Fairford, which has been used by US bombers to launch air strikes against IranS6