HAMPSHIRE police have helped launch raids on 30 addresses linked to animal rights extremism across the UK and Europe.
About 300 officers were involved in the operation, which was part of an investigation into criminal activity linked to animal rights extremism, a Hampshire police spokeswoman said.
The operation was carried out by UK and European police forces and other agencies.
The spokeswoman said: "Police officers are executing warrants to enter and search premises at 30 addresses throughout the UK and Europe.
"The warrants have been obtained as part of an ongoing investigation into criminal activity associated with animal rights extremism.
"This is a substantial police operation led by forces from the South East region and supported by a number of other UK and EU police forces and European law enforcement agencies.
"Around 300 police officers and supporting staff are involved in the operation.
"There is ongoing police activity at the addresses, and officers are working with the local communities to minimise any disruption."
Other UK police forces involved in the raids include Sussex, Kent, Surrey and Thames Valley.