Police have re-released images of suspected graffiti vandals who they believe are responsible for causing thousands of pounds worth of damage to buses.

Officers are asking for help in identifying the suspects, who are thought to have scrawled personalised graffiti marks, or tags', on buses last year.

The CCTV images, released by the police graffiti team and the bus operators, show teenagers daubing graffiti in buses and etching names onto windows.

Police believe the suspects live in the borough as they were caught on cameras around Colindale, Burnt Oak and Brent Cross.

Arriva's 142 bus service - which travels along the A5 (Edgware Road) from Brent Cross to Watford Junction, through Edgware, Burnt Oak, Colindale and West Hendon - has experienced some of the highest levels of vandalism in London, with 84 incidents of criminal damage reported since November 2004.

Metroline's 32 service, which runs from Edgware to Kilburn, through Burnt Oak, Colindale, West Hendon and Cricklewood, has also been badly hit.

Picture number one, of a suspect using a London Sovereign 292 service, was captured at 8.30pm on September 21, along Edgware Road between Hale Lane and Burnt Oak.

Picture number two is of a suspect on Metroline's 32 bus service at West Hendon Broadway, at 11pm sometime in November.

The youth in picture number three was on the 32 bus along Edgware Road on August 16 at around 11pm.

Picture number four shows a young man in a baseball cap on the 142 bus in West Hendon Broadway at 8pm on September 27. He is suspected of causing £150 worth damage with the tag EASER'.

The suspect picture number five was on the 142 bus at about 9pm on March 21, travelling through the Stonegrove estate, Burnt Oak. The tag drawn in the incident was North West terroist' sic.

The suspect in picture number six, wearing a distinctive hat with 76' on it, was travelling on a 142 bus near Brent Cross shopping centre on April 17 last year. The tag FB47' was scrawled around the bus.

These images have also been released to schools across the borough.

Barnet police said that more than £18 million worth of damage is caused on buses in the capital every year.

Operation BusTag was set up in January last year to find the culprits. Punishments range from losing the right to free bus travel through to community orders and even imprisonment.

PC Graeme Day: "We are appealing to family, friends, neighbours, schoolteachers and anyone else who thinks that they can identify either the taggers or the tags to contact us."

If you know any of the teenagers pictured in the CCTV photos, call Crimestoppers, anonymously, on 0800 555 111 or PC Day on 020 8733 3528.