Two arrested after Plymouth police follow 2.5 mile blood trail
Two men have been arrested after police followed a 2.5-mile (4km) blood trail from the scene of a serious attack.
A man in his 40s was found with severe head injuries at 02:25 BST in Plymouth, and remains in a critical condition in hospital.
The blood trail was traced back to an address in a different part of the city where it is believed he was injured.
Armed officers arrested two men from Plymouth, aged 67 and 52, on suspicion of grievous bodily harm.
Later, the 52-year-old man was taken to Derriford Hospital after there were "concerns for his health".
The force has referred the matter to the Independent Police Complaints Commission (IPCC), it said.
It was first thought the injured man, who was found by a member of the public, had been hit by a vehicle.
Police followed the trail on a indirect route from Wingfield Way to Melbourne Street, which can ordinarily be reached along a half-mile (1km) path.
Sgt Harry Tangye tweeted about the incident, and said an armed response vehicle and other units "boshed" the door of the property where the blood was found.
Ch Supt Paul Davies said: "The inquiry is at an early stage and we are currently trying to ascertain how the man sustained his injuries before being found in the street.
"We believe that members of the public may have seen him making his way from the location where we suspect he received his injuries to Wingfield Way, where he was found by a member of the public."
Wingfield Way was closed while examinations of the scene took place, and a police guard remained at the property in Melbourne Street.