A convicted murderer has been sent back to jail for posting offensive messages about victims of terrorism on social media.

Andrew Harding drunkenly posted abuse about victims of the Christchurch mosque shootings on Facebook in March.

Harding, 51, of Manderston Road, Newmarket, admitted two counts of sending a grossly offensive message by public communication network at Suffolk Magistrates' Court on Tuesday.

Prosecutor Lesla Small said the posts - published at about 7.30pm and 8pm on the day of the attacks - were reported to police by a Facebook user on March 20.

"The shootings received worldwide media attention and were labelled acts of terrorism," added Ms Small.

She said both posts included insults about victims and made reference to video of the event.

Police arrested Harding and found two videos of the attack on his mobile phone, along with evidence proving he posted the messages on Facebook.

The father-of-three told police he had "grainy recollection" of the post, which he said were completely out-of-character and posted after having consumed 18 pints of lager.

Malcolm Plummer, mitigating, said Harding had been frustrated and angry at the loss of his job three weeks earlier, and had not realised the messages would reach so many other Facebook users.

"He was out of work and angry at the world. Hence, the drinking," added Mr Plummer.

"He doesn't consider himself a racist, or to dislike Muslims.

"Since this, and because of his past, he has lost at least two jobs, and realises it's down to his own stupidity.

"However unpleasant, the messages were brought about by frustration and drink."

The court heard how Harding was convicted of murder in November 1991 and subject to lifetime licence conditions upon release, including a supervision order, which was removed in 2016 following reassessment by the probation service, but will now be reactivated.

Before jailing Harding for 10 weeks, presiding magistrate Graham Higgins said the offences were targeted, timed, and aggravated by Harding's alcohol consumption and their basis on religious belief.

"We put these offences into the category of high culpability and greater harm," he added.