Police will be able to travel on buses for free

It is hoped that an increased police presence on buses will prevent incidents such as stone throwing at buses and aggressive behaviour.

The all-Wales scheme - to be launched in Cardiff on Thursday - is open to all uniformed officers and police community support officers.

It was organised by the assembly government-funded Bus Users UK.

The Bobbies on Buses scheme is supported by all four Welsh police forces. It follows a number of recent incidents involving anti-social behaviour on bus routes throughout Wales.

A decent, safe and secure public transport system is one of the hallmarks of a civilised society Leo Markham, Bus Users UK

Leo Markham, from Bus Users UK, said problems on the buses included feelings of unease while waiting or travelling on the bus, to social exclusion when services were withdrawn following incidents like stone throwing.

"The cost to bus operators is enormous and it is the bus user who ultimately pays the cost with higher fares," he said.

"We see this scheme as the start of even better co-operation between police and bus operators and one which can give a greater feeling of security to bus users.

"A decent, safe and secure public transport system is one of the hallmarks of a civilised society."

He added that a better incident reporting scheme was also being implemented to assess the scale of anti-social behaviour on bus routes around Wales.

Gwent Police Assistant Chief Constable, Bill Horne gave his support to the scheme, describing it as a "valuable tool".