A 22-year-old man had been arrested on suspicion of section 18 assault after a "petrol bomb" device was thrown at police officers in Liverpool.
Merseyside Police said that the man from Anfield has been taken to a police station to be interviewed.
Inquiries are still ongoing into the incident which happened in Townsend Lane, Anfield on Tuesday.
Four officers were injured in the attack and required hospital treatment for minor burns.
The incident took place after a warrant was executed shortly before 4pm at an address in Lampeter Road in which a man made his way on to the roof of the nearby Dockers Club in Townsend Lane.
As the officers cordoned off the area in a bid to speak to him and persuade him to come down, they were assaulted.