Six people remain in custody in connection with an incident in Essex that saw two police officers hospitalised after having petrol thrown over them.
Two women, a boy and three men were arrested on Sunday in Canvey, Basildon, after police were called regarding an incident involving a stolen motorbike.
While making an arrest, Essex Police officers were threatened with a hammer and a number of them had petrol thrown in their faces.
Two officers were taken to hospital to have their eyes washed and others were doused with water at the scene but the force said they did not anticipate any "long-term harm" for those affected.
Police were responding to reports that a motorcycle was being driven dangerously along footpaths, through underpasses and on roads in the area at 4.30pm.
Essex Police followed the bike with assistance from the police helicopter and the rider was later detained in Ward Close.
Superintendent Jonathan Baldwin said: "I am proud of the way my officers dealt with this incident, acting professionally and with dignity in the face of certain individuals who appeared intent on causing trouble.
"To be assaulted while simply doing our jobs - helping to keep our county safe and dealing with criminal and violent behaviour - is completely unacceptable under any circumstance.
"But, to have petrol thrown over their heads and in their eyes as my officers experienced today, is a despicable act of violence which we will seek to prosecute to the full extent of the law."
Steve Taylor, chairman of Essex Police Federation, said: "This was a despicable, sustained attack on our Essex Police colleagues dealing with criminals in our county.
"Having been physically attacked whilst arresting two suspects, five brave police officers were also doused in petrol - two of whom were hospitalised as it was in their eyes and mouth.
"Police officers do not come to work to be attacked - and we join right-minded members of the public in being appalled at this latest incident.
"Thankfully our colleagues involved are recovering but this scary situation could have been so much worse. The Force and Federation will continue to support them.
"More than 750 Essex Police officers were assaulted in the line of duty last year - we must ensure the full force of the law is used against those who think attacking police officers is acceptable."