A bus explosion that killed three people near Damascus was an accident, according to Syrian officials.  Interior minister Said Mohammad Sammour ruled out a terrorist attack in a statement on state-run Syrian TV. He said the bus driver and two garage workers died when a tyre exploded. "There was no terrorism factor behind the bus incident," he said. "The bus entered a petrol station to h More..ave one of its burst tyres inflated and the tyre exploded. Earlier reports suggested a bomb had struck the bus, killing at least six people in what would have been the latest in a series of terrorist incidents. The blast took place in the busy suburb of Sayyida Zainab. The area is home to a shrine dedicated to the granddaughter of the Prophet Muhammad and attracts Shi’ite Muslim pilgrims. The rear part of the bus was blown open by the force of the explosion, which shattered windows in surrounding buildings. The blast hit as Saeed Jalili, Iran's chief nuclear negotiator, visited the city for meetings with Syrian officials. Reporters have been banned from reaching the site.