A police officer is battling serious injuries in hospital after being sprayed with ammonia fluid while attending an emergency call.
The officer from Lancashire Police was one of seven who were sprayed with the substance after forcing entry to a building on Ash Grove in Darwen, following a call reporting a domestic incident.
One of the officers, a Sergeant, suffered serious damage to his eyes, throat and respiratory system and remains at Royal Blackburn Hospital - the other officers suffered less serious injuries and were discharged.
The suspect, a 46-year-old man from Darwen, escaped through a first floor window but was arrested a short time later and is being held on suspicion of of causing grievous bodily harm with intent.
A police spokesperson described the incident, which occurred around 2am early Tuesday morning, as "shocking".
Superintendent Andrea Barrow added: "My thoughts are with him and his family and I wish him a speedy recovery and look forward to his return to work."
Chief Constable Andy Rhodes said: "My thoughts are with this officer and all of those affected by this incident, which shows once again the dangers that officers face and how they put their lives on the line each and every day to protect people."
Police enquiries are ongoing.