At least 20 people were killed and another 27 injured in explosions triggered by solvent oil that leaked from a rear-ended tanker truck in Guangzhou, Guangdong province, on Friday morning.

The solvent oil flowed down to the drain under on the Nangang section of a flyover along the Yanjiang Expressway, then caught fire and burned buildings and a container yard.

The accident between two trucks happened at 4:30 am, according to the Guangzhou city government. The tanker truck was carrying 40 metric tons of solvent oil.

Most of the people killed were sleeping in a wood product market under the flyover, according to those who escaped from the fire.

The drivers of the trucks were not killed, according to witnesses. Both trucks are registered in Hunan province.

Twenty-nine fire engines and 185 firefighters were dispatched to extinguish the fire and to rescue injured people. It took four hours to put out the fire, which covered more than 2,000 square meters, according to the Yangcheng Evening News.

After an on-the-spot meeting to arrange the rescue and investigation, Guangzhou Party chief Wan Qingliang comforted the injured and their relatives in hospital while Mayor Chen Jianhua stayed at the blast scene to lead subsequent work.

According to the city government, the accident had not polluted the air and water in the adjacent area.

Luo Zhenzu, the 50-year-old owner of a wood processing workshop about 400 meters from the blast scene, managed to escape with his four family members.

"I was awakened by two loud bangs at about 5:05 am and saw the big fires. I grabbed my 8-month-old grandson into my arms, then awoke other family members and rushed out of the house," Luo recalled.

His son, Luo Pan, said he became panicky when finding his quilt was on fire. He ran away with only his underpants on, leaving all the valuables — computer, mobile phone, about 80,000 yuan ($12,560) in cash — behind in the house.

"I don't know from whom I can claim compensation. The local government hasn't sent people to help us settle down yet," the 18-year-old said. He had been waiting outside the blockade for eight hours when he talked to China Daily.

According to Luo Pan, there were about 80 small wood processing factories in the market under the flyover. He estimated that about 20 were burned down in the explosion.

"Most of the buildings were built with bamboo. We can't afford steel because we have been forced by the urban management officers to move from one place to another," said Luo Pan, admitting that none of the factories has a business license.

He added that most of the approximately 200 people working and living in the market come from Longhui village in the Shaoyang city of Hunan province.

Gu Chunhua, a truck driver, was made dizzy by the smell of the leaked oil when he drove by the area before 5 am.

"My truck stopped because my engine went off," Gu recalled. "I sensed something wrong from the unpleasant smell so I escaped from the truck at once."

"The explosion went off about 10 minutes after I ran away, and I was blown to the ground and grazed my arm," said Gu.

According to Guangzhou Daily, at least three motorcycles and six light-duty trucks were burned down to their frames in the explosion.

Luo Pan said the explosion might have been triggered by the first of the three motorcycles ahead of Gu's truck.

"One of my neighbors told me that she saw the explosion starting from where the motorcycle stopped. The oil on the ground might be ignited when the motorcycle driver tried to restart the engine," he said.

An unknown number of traffic police officers were handling the traffic accident on the flyover before the explosions, Gu said. Whether the officers were injured by the blast remains unknown.

The section of the highway affected by the accident was sealed off and road experts were organized to test its safety.

Zheng Erqi contributed to this story.

Contact the writers at liwenfang@chinadaily.com.cn and xujingxi@chinadaily.com.cn