YINCHUAN, Jan. 5 -- Police have arrested a suspected arsonist as the death toll from a bus fire in northwest China rose to 17 with three more bodies found at the scene, said an official on Tuesday.

The dead included eight males and nine females. All the 32 injured, aged between 20 and 65, are being treated at Ningxia Medical University General Hospital in Yinchuan, capital of Ningxia Hui Autonomous Region, said Ma Kai, vice mayor of Yinchuan, at a press conference.

Police arrested suspect Ma Yongping in an incomplete building in Helan County at 4:30 p.m.. His trousers were burnt.

Six of the injured are in a serious condition, including one critical, said Jia Shaobing, deputy president of the hospital. The others are stable.

The incident happened at around 7 a.m. Tuesday in Helan County, Yinchuan, where a bus caught fire in front of a furniture store.

"I was sitting at the front of the bus when suddenly people started screaming 'Fire! Bus on Fire!'," Hu Yuexiang, 26, recalled. "When I turned around, the flames were racing toward me and quickly my shoes were on fire."

"I thought the bus was about to explode, and I was going to die," Hu said. "Then the door opened and we all rushed out."

Hu said he wanted to film the fire, but the bus quickly "turned into a skeleton."

The bus driver sustained minor burns in the incident and is assisting police with the investigation.

The 84-seater bus had about 40 people on board when it caught fire.

The bus, which was bound for Yinchuan Railway Station, belongs to state-owned Yinchuan Public Transport Co. Ltd. The company has begun a safety check of all its vehicles following the incident.

Public buses are operating normally in Yinchuan.