A Dublin man who stabbed two innocent bystanders during a 'Swedish House Mafia' concert in the Phoenix Park in 2012 has been jailed for four years.

Raymond Donnan (24) of Greenfort Crescent in Clondalkin was in a group of eight men and four women that took part in separate attacks on other concert-goers.

The court heard he had consumed an entire bottle of rum after security staff had stopped him from bringing the alcohol into the park.

He pleaded guilty at Dublin Circuit Criminal Court to violent disorder and assault causing harm to Andrew England on July 7th 2012.

Garda Sergeant Shane McCartan told Shane Costelloe BL, prosecuting, that an off-duty garda was at the concert himself when he witnessed Donnan and the others set on another man for no apparent reason.

He said that Donnan stabbed this first victim three times in the torso while the off-duty garda went off to find other gardai and security staff.

He returned with these to find the gang attacking Mr England. One man struck him over the head with a bottle and then used the broken bottle to stab him in the arm.

When Mr. England tried to get away Donnan stabbed him multiple times in the back. Sergeant McCartan testified that the blade of the knife was four to five inches long.

he said that at this point, gardai were preparing to safely remove Donnan from the crowd and arrest him - but he and three other men immediately attacked a third victim, punching and kicking him.

Gardai then moved in, surrounded Donnan and arrested him.

The court heard Donnan's previous convictions include sale or supply of heroin and possession of a Stanley knife blade at in Dublin city centre.