Chinese state media say a bus traveling on an expressway has scraped a car, crossed the center divider and smashed into another oncoming bus. That bus then veered off the road, killing 13 people on board.
The accident occurred around noon Sunday in eastern Shandong province.
China Central Television says the second bus rolled over as it fell down a slope from the expressway.
The official Xinhua News Agency says 13 people on that bus died and nine others are seriously injured.
A man on duty at the Shandong provincial traffic management bureau says the accident is still being investigated.