POLICE have warned they will take action against trolls posting offensive messages on Facebook - and have already secured one conviction. 

A 31-year-old man from Barnsley has begun a five-and-a-half month prison sentence for posting an offensive message on the force's Facebook page.

He has been convicted of sending an electronic message which was grossly offending in character and was jailed on 10 June.

In a statement posted yesterday, the police said: "Social media followers made it clear they want us to take a stronger stance against this type of behaviour and asked us to 'control the trolls.'

"Whilst everyone has a right to an opinion, posting threatening or hate-filled comments on posts will not be tolerated."