One side of the Jack Lynch Tunnel is closed until further notice after an overheight truck struck the entrance to the southbound tunnel causing what has been described as 'very serious damage'.

Officials say the southbound lane - used by traffic from Dublin and Waterford - is now out of action and traffic is now being diverted into the northbound lane.

No structural damage was caused to the tunnel, but major damage has been caused to electrical equipment such as lights, monitoring equipment and electrical cabling.

The tunnel's Engineering Manager, Dan O'Neill, says the southbound bore is likely to be closed for a substantial period of time.