Brian Clarke, from the Prison Officers Association, said the attack happened as guards were dealing with a prisoner who was on "special conditions" and required three officers to look after him.

BBC: Winson Green Prison: Four officers 'glassed' by inmate

Dundee have already paid a similar fee to Livingston for striker Leigh Griffiths and have also snapped up Brian Kerr from Inverness, Steve Clarke from Clyde and Chris Casement from Ipswich this summer.

BBC: Dundee capture Thistle's Harkins

Points from Brian Mallon, Aaron Kernan, Ronan Clarke and Oisin McConville put the Orchard men three points clear.

BBC: SPORT | Northern Ireland | Gaelic Games | McConville fires Armagh to glory