A 20-year-old man is detained at Heathrow Airport on suspicion of attempted murder.
A man has been arrested on suspicion of attempted murder at Heathrow Airport as he was about to leave the country, Met Police said.
The 20-year-old is being questioned by detectives investigating a suspected hit-and-run, which left two people in critical care in hospital.
The men were injured in the early hours of Sunday when a car hit them and two others on Kingsley Road in Hounslow.
The other pedestrians were treated for non-life changing injuries.
The driver of the car, a Nissan Qashqai, did not stop at the scene. It was found by police in Hounslow a short time later.
The Met Police said the man was arrested shortly before 19:00 BST on Sunday. The force said he had booked a flight and was planning to leave the country.
A second man was also arrested nearby on suspicion of assisting an offender.
Det Ch Insp Andy Thrower said it was “a serious incident that would have shocked the local community”.
Anyone with information has been urged to contact police.