Six people have been arrested over alleged mistreatment and neglect of residents in a care home.
The arrests follow a five-month investigation into a number of reported incidents at Hillcroft nursing home in Slyne-with-Hest, Lancaster.
The mistreatment is said to have taken place within the home's challenging behaviour unit which cares for vulnerable adults with advanced Alzheimer's, police said.
Two men, aged 34 and 26, and four women aged 26, 27, 53 and 59 were detained today at separate addresses in Lancaster and Morecambe.
They are being questioned on suspicion of committing offences under the Mental Capacity Act 2005 and Mental Health Act 1983.
Lancashire County Council's Adult Services Social Care department made police aware of a complaint they had received about the level of care provided to some residents at the home.
The allegations date back to December 2010 with the most recent being reported in February 2012, police said.
Ch Supt Richard Bayly, Divisional Commander at Northern Division, said: "These arrests are a culmination of a thorough investigation into serious allegations of mistreatment of residents at Hillcroft Slyne nursing home.
"The inquiry is complicated and we have a team of specialist detectives working on this case who are also offering support to those families who may have had loved ones identified as being allegedly mistreated."