Have a go gran Joan Heath, 73, stopped a young thief stealing a sat nav from a coach.

Mrs Heath, of Stratton, blocked the 16-year-old thief's path and kept him prisoner until police arrived.

The youth ran onto the coach bound for Bournemouth and was about to espace with the sat nav while the driver was loading suitcases at Swindon bus station until Mrs Heath stepped in.

"I acted on impulse," said the grandmother of five.

"I thought it was strange he was getting on the bus having no suitcase after he shouted to the bus driver where you going to?' "I had to do something so I just stood at the bottom of the stairs to the bus entrance with both hands on the rails.

"It all happened so quickly and before I knew it he slipped and knocked me to the floor and I landed on top of him.

"Then a few people from the bus realised what had happened and caught the boy.

"One had his arm held firmly behind him.

"The boy probably thought we were on a silver threads outing, so I think it's great the old folk caught him."

Mrs Heath was left with a bruise on her elbow, which she landed on, but came away relatively unscathed.

She added: "Looking back it was probably quite a foolish thing to do, he could have had a knife or any sort of weapon.

"Maybe if I had had more time to think about the situation I might not have done anything."

One of the passengers on board the bus paid tribute to Joan's heroism.

Jeff Davies, 67, from Redditch, in Worcestershire, said: "This kid came up as bold as brass and looked as strong as an ox.

"I couldn't believe Joan stopped him getting off as without her he would have got away with it.

"I thought she was a very brave and courageous lady.

"I think people in Swindon should feel proud of this plucky lady."

Mike Merron, the chairman of The Coach Holiday Warehouse, based in Cheltenham, said Mrs Heath was brave to protect the bus and they were indebted to her valiant interception.

A spokesman for Wiltshire police said: "The youth was arrested for the attempted theft of the sat nav."

He was released on bail as police continue their inquires.

After the incident Mrs Heath said she had a lovely five-day trip in Dorset with her husband of 50 years, Ken, 79.