Do you know more? Text 0424 SMS SMH (+61 424 767 764), email us or direct message on Twitter @smh One of the flyers handed out by bus drivers in Sydney this afternoon. Credit:Liam Phillips The move came after a video was released of an explosion on a bus in July. The Mercedes-Benz model 0500 LE CNG bus operated by the State Transit Authority, caught fire on Beauchamp Street, Hillsdale, while returning without passengers to the Port Botany Depot, the Office of Transport Safety Investigations said in a report. "The bus operator was alerted to a fire in the rear of his bus by a passing motorist. He stopped and tried to extinguish the fire in the engine compartment with a portable fire extinguisher but without success. "NSW Fire and Rescue from three stations attended, along with NSW Police. However, they were unable to extinguish the fire which had spread to the interior resulting in the bus being totally destroyed," the report said.

"Today we have obtained evidence that a fire on board an STA bus in July was more than just a fire," the president of the bus & tram division of the NSW Rail, Tram and Bus Union, Gary Way, said in a statement. "In fact, video evidence conclusively shows that the back of the bus exploded," the statement said. It's a snap strike: minister But the state government has criticised the union for orchestrating a "snap strike", which the Transport Minister Gladys Berejiklian told Parliament coincided with pay negotiations today. "Today the RTBU did hold negotiations regarding their new award and it's a coincidence that on the same day the RTBU is arguing about wages and conditions they call this snap strike inconveniencing commuters," she said.

Drivers are concerned they may be driving around in ticking time bombs. Ms Berejiklian said the incident that led to the withdrawal was still being investigated but said precautionary tests on buses of the same model type had revealed there was no risk to the public. "As a precaution, State Transit, after that incident on July 29, inspected the remaining 254 vehicles, every single one was inspected, the same model, and found no risk to passengers," she said. "I am disgusted bus drivers are deserting their passengers - including schoolchildren - in the afternoon peak," she said in statement. Ms Berejiklian said the State Transit Authority was seeking urgent action in the NSW Industrial Relations Commission to get the drivers to end their illegal action and to get back on the road.

The union, however, denied that the withdrawal of buses was related to the award. "We are negotiating an award but this has got nothing to do with our award," RTBU secretary Chris Preston told ABC Radio. "We've been negotiating an award for six months." Buses unsafe: union Mr Way said: "One of the state transit gas-powered buses caught fire, finished up exploding and burnt to the ground to the point where the whole frame was buckled and there was nothing left of the rest of the bus," he said.

The union said it had written to the STA five times since the incident but had not received a reply. "Had there been people on the bus, any people, let alone schoolchildren or the elderly, it would have been catastrophic," Mr Way said. "Luckily the driver got off before it all went up. They’re unsafe. Until they can demonstrate that they are safe ... we’re not going to drive them. "Given the shocking information that has come to light today, it appears that STA has been withholding the full extent of the dangers being faced by passengers," he said. "This situation is completely unacceptable. Drivers are concerned they may be driving around in ticking time bombs.

"Under these extraordinary circumstances, the only responsible course of action is to immediately take STA's fleet of gas buses off the road until these serious safety concerns are addressed," Mr Way said. Chris Preston of the RTBU said the depots affected did runs for all of Sydney. Go and wait or take a ferry A spokeswoman for the STA said she was unable to provide any specific information about disruptions to routes. "What we’re advising people to do is either go to their nearest bus stop and just wait for buses," she said. "If they prefer they can use their bus ticket to either catch a bus or ferry."

A spokeswoman for the Transport Management Centre said: "Some buses will still be running, but may not be to timetable." Northern Sydney and northern beaches services as well as private bus services are not affected. The withdrawal will not affect STA buses in Newcastle, which are fitted with devices alerting drivers to possible fires in the engines of of buses. Sydney's government bus fleet consists of 2500 vehicles, of which 700 are gas powered. Loading

The drivers have stopped driving the gas buses which affect vehicles at five depots, located in Ryde, Kingsgrove, Leichhardt, Waverley and Port Botany. - with AAP