Chinese police are holding four people as part of the investigation of a fatal bus accident in northwestern China's Shaanxi province that claimed 35 lives.
A bus carrying 46 people fell into a ravine some 30 meters deep near a forest park in Chunhua county on Friday afternoon.
Twenty-five people died instantly and ten passed away at hospital. The rest are being treated for injuries.
This is the country's worst road accident in months.
Passengers on the bus were residents from nearby cities, mostly elders, who joined a two-day sight-seeing and shopping tour organized by a Xiangban trading company in Xi'an, the provincial capital. They were on their way home when the accident occurred.
The company leased four buses for the 193-member group. The rest were safe.
Police are now holding four people - the bus driver, surnamed Wang, the bus owner, surnamed Liang, the legal representative of Xiangban trading company, surnamed Zhang, and the organizer of the two-day tour, also surnamed Zhang - for investigation of the cause of the accident.
Vice minister of public security Huang Ming has also arrived in Chunhua to oversee investigations.
Fatal road accidents are a serious problem in China, where traffic regulations are often flouted.
Traffic authorities reported 41 million violations in the 40-day Spring Festival travel rush in February and March alone.
Forty-four people were killed and 11 others injured after a tour bus fell into a valley following a three-vehicle pile-up in August last year. A month prior to that, 43 people died in a fiery explosion after a van loaded with alcohol rear-ended a passenger coach in central China's Hunan Province.