Bus passengers were moved to safety after the driver saw 'white fumes' coming out of the vehicle on the Hastings to Bexhill link road.
The Stagecoach south east bus was stopped in Combe Valley Way and passengers were moved to safety, according to Rother Police.
The cause of the fumes was 'a coolant failure', according to police.
Police praised the 'quick thinking' actions of the driver.
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