Police have urged communities in Batley and Dewsbury to not turn to vigilante action following a string of violent robberies in the area.
In one, a couple in their 80s were threatened and robbed in their Savile Town home.
Tensions came to a head on Thursday night in Charles Street, Ravensthorpe, when violence broke out between a 150-strong mob after five people were injured in a collision with a car.
A West Yorkshire Police spokesperson said: “We have a number of teams dedicated specifically to deal with these matters and are working very closely with our neighbouring districts of Leeds and Bradford to solve the crime and bring those responsible to justice
“Unfortunately and very sadly a number of people within our community have decided to take it upon themselves to try and police their local streets which is raising concerns and fears unnecessarily and have resulted in at least two serious incidents.
“We ask that this behaviour cease immediately as it is only causing harm to the wider community.
“We have numerous resources working during the day and into the night all of whom will be patrolling the streets, working with our communities and gathering any information or intelligence that you may have. Please speak to the officers and pass on any information you may have to them.
Policing the streets of Dewsbury and Batley is the preserve of the police and we cannot allow individuals to take on this role and in effect act as vigilantes.
“We know or communities do not want this and cannot and will not allow this to continue.
“We are aware of a large amount of information being shared by the community on social networks.
“A lot of this information is not reaching the Police and is not being verified as being correct therefore unnecessarily raising fear and confusion within our communities.
“We are aware that a number of members of the public have circulated names and/or images of people they believe could be potential suspects online on social media websites.
“While we appreciate that people are trying to help, this could actually seriously harm the police investigation and hamper any prosecution case further down the line.
“Anyone with information about these crimes are urged to provide information to West Yorkshire Police directly by calling 101.
“Information can also be passed to independent crime-fighting charity Crime Stoppers anonymously on 0800 555 111 or online.”