Image copyright Family photo Image caption John Miller was knocked over by an off-road bike in Llanrumney

Police are searching for a hit-and-run motorcyclist who left an 84-year-old man badly hurt on a road.

John Miller was hit by a bike on Mount Pleasant Avenue, Cardiff, when the rider allegedly lost control while "pulling a wheelie".

His family and residents said anti-social use of off-road bikes had become a major problem around Cardiff.

Police said one person has been convicted and bikes seized as part of an operation to tackle the wider issue.

Image copyright Family photo Image caption Three members of St John Ambulance helped Mr Miller at the scene

The retired glazier was walking home along the pavement in the Llanrumney area of the city when he was struck by an orange off-road bike at about 17:15 BST on 22 June.

After getting back onto his bike, the rider, in a white t-shirt, drove off leaving Mr Miller lying in the road.

Passers-by, including an off-duty nurse and three members of St John Ambulance, treated him before he was taken to hospital with injuries to his face, shoulder and stomach.

Image copyright Family photos Image caption The rider drove off from the scene of the accident

"Granddad was very lucky to have such professional people walking past and we're so grateful," said his granddaughter Kate Miller.

"He is still suffering because of the pain, he's very shaken up and won't leave the house due to how his face looks.

"All the family are trying to rally around to make him comfortable - but we all want the guy involved caught.

"I just hope one of his mates that witnessed this will come forward with a name, so the streets are a little safer."

Police are appealing for information or any dashcam or CCTV footage.

However anti-social use of off-road bikes is a continuing problem across all parts of Wales.

One Cardiff resident, Elaine Jones, posted on social media: "I always see these bikes riding through from Llanishen through Pentwyn and over to Llanrumney - pulling wheelies along main roads with no consideration for anyone - even through the lanes driving really dangerously."

South Wales Police said one person has been convicted and bikes seized as part of Operation Red Manna - to tackle the wider "illegal and dangerous" issue in other parts of the city.

A spokeswoman said: "We ask the community to tell us who is riding these bikes - who they are, where they live and if possible photographs and descriptions of the bikes they use - so we can take action.

"We would also remind parents of their responsibilities in relation to their children using off-road bikes."

Gwent Police are also appealing for information as part of Operation Harley which is targeting the problem around Newport.

Sgt Roland Giles said: "We share the community's frustrations with these bikes and their riders, who often show no regard for their fellow road users, neighbours or pedestrians - not to mention their own safety."

The force said bikes have already been seized in Duffryn.

North Wales Police will also run a series of operations during the summer following complaints across the region.

Image copyright North Wales Police Image caption Police have the power to seize bikes and cars which are used in a way which causes harassment, alarm or distress

Operations in Denbighshire and Wrexham last month saw 20 riders dealt with for offences ranging from illegal number plates, no insurance and driving offences.

Dyfed-Powys Police and North Wales Police also launched a joint operation to target illegal off-roading in the Dyfi Forest, near Machynlleth, following complaints.

Insp Eddie Cowan, of Dyfed-Powys Police, said: "The best way forward is for these riders to find a commercial motorsports site, an off-road centre, or by joining a reputable club specialising in off-road activities."