Firefighters arrived at the scene around 6.30 am to find the wooden bridge still smouldering and unusable.

The refurbished bridge was opened at the end of 2003 and links the path along the Scouring Burn with an area of community land beside Glasgow Road.

The path is a popular route for dog walkers and, with playparks and football pitches nearby, an attraction for children.

It was sealed off today, forcing dozens of cyclists who use it to get from the west of Perth to the city centre to take alternative routes.

Local woman Nicola Davidson, who uses the path to walk her dog, said, “I can’t believe people could be so stupid.

“The whole bridge has obviously been set alight and was smouldering for some time.

“When I saw it, the wood was still hot and damaged — and imagine if a young child had tried to cross it on the way to school.”