Rescuers work at the accident site where an 80-meter-long section of an expressway bridge collapsed due to a truck explosion in Mianchi County, Sanmenxia, central China's Henan Province, February1, 2013. At least 8 people died and 13 others injured after the explosion. The exploded truck was loaded with fireworks, according to an initial investigation. Search and rescue efforts are under way and traffic control was imposed on the expressway. Photo: Xinhua

The death toll from an express bridge accident in central China's Henan Province has risen to 10 and four suspects have been arrested, the China Central Television (CCTV) website reported Saturday.

The accident occurred around 9 am Friday, when a firecracker-laden truck exploded on a 30-meter-high bridge in Mianchi county, Sanmenxia city, about 193 kilometers west of the provincial capital of Zhengzhou.

The report quoted police sources as saying that the truck did not have a permit to transport hazardous materials. Police said the firecrackers were to be delivered to a department store from northwest Shaanxi Province.

Southern Metropolis Daily said the truck came from the city of Yichang in Hubei, a neighboring province of Henan. A renowned Henan-based firework dealer also told the newspaper that the truck was heading towards northwest China.

Another CCTV report said the explosion occurred after a rear-end collision chain on the bridge, including the explosives-laden truck. However, local police said they could not rule out other possibilities.

An 80-meter-long section of the southern bridge lane collapsed after the explosion, according to the rescue workers at the scene.

The rescue workers said Friday night that six trucks and two cars were pulled from debris by 9 pm, and further search and rescue efforts remain underway.

The expressway bridge, with bi-directional four lanes, opened to traffic in 2001 after three years of construction. The last test in 2011 revealed that no safety risks.

The Ministry of Public Security has dispatched a team to direct the rescue work and investigate the cause of the accident.

The bridge is part of the Lianyungang-Khorgas Expressway. It connects the cities of Lianyungang in east China and Khorgas in northwest Xinjiang on the border with Kazakhstan.

Traffic controls have been put in place on the expressway.