A police officer has suffered severe facial injuries while trying to detain a suspect in the Staple Hill area of Bristol, Avon and Somerset Police said.
The officer is in a stable condition and will have surgery.
A force spokeswoman said the officer was injured “in the line of duty” while detaining a 20-year-old suspect.
It is understood that it is not clear whether the officer was attacked or sustained injuries by falling.
The officer has not yet been able to give a full account of what happened because of ongoing medical treatment.
In a statement, Avon and Somerset Police said: “At about 7pm yesterday (August 20), a suspicious vehicle was seen by officers outside a building supplies company in Staple Hill. The car drove off and was spotted by officers a short time later in Kensington Road.
“When officers approached the vehicle, the three occupants got out and ran off in different directions.
“One of the suspects was seen heading along a footpath off Acacia Road and an officer chased after him. While detaining the suspect the officer has suffered some severe facial injuries. He was taken to hospital where he will undergo surgery. He is in a stable condition.”
A 20-year-old man has been arrested on suspicion of possession with intent to supply a class A drug and a 37-year-old man has been arrested on suspicion of being concerned in the supply of controlled drugs.