BEIJING, July 2 (Xinhua) -- China's work safety watchdog on Saturday ordered safety checks of coaches nationwide after 26 people died in a bus accident in north China's Tianjin City.

The accident occurred on Friday evening when a coach carrying 30 people broke a guardrail on the Baodi section of the Tianjin-Jixian expressway and fell into a ditch, according to a statement from the city's emergency response office.

The driver lost control of the vehicle due to a flat tire, and the four survivors, including a ticket seller, a co-driver and two passengers, sustained minor injuries, it said.

The administration ordered local authorities to launch safety inspections on coaches, step up training of drivers, and crack down on overloading, speeding and fatigued driving to prevent major accidents.