A man has been cautioned by police after racist and offensive comments opposing plans for a Muslim prayer centre in Shrewsbury were posted on a social media site.
West Mercia Police said the Facebook user, aged in his 20s and from Shrewsbury, admitted using words or carrying out behaviour likely to stir up racial hatred.
The man, who has not been named, was arrested on Thursday as part of inquiries into Facebook posts related to plans to use a former register office in the city for prayer meetings and day care.
Two other men previously arrested over comments on Facebook are on police bail, and officers have spoken to two further individuals who have agreed to remove their remarks from the site.
The policing commander for Shropshire, Superintendent James Tozer, said: "West Mercia Police takes all reports of racism extremely seriously and a full investigation into these complaints is now under way.
"With regards to this particular issue, there has been a local prayer room in Shrewsbury for the last 10 years and its users are a welcome and well-established part of our community.
"We are working closely with them and other community groups to prevent any escalation of this situation."