The death toll from a little-reported road explosion was disclosed Thursday to be a much higher 31, nearly two weeks after the blast shook a highway tunnel in northwestern China.

The city government of Jincheng in Shaanxi province said a team assembled by the State Council to investigate the blast met Thursday in the city to brief on the latest developments. It said another nine people were missing.

The city statement came minutes after China concluded its annual meeting of its ceremonial congress in Beijing, raising questions if the case had been purposely given little attention to avoid disruption to the convention.

The crash March 1 involved more than 40 vehicles, including those carrying hazardous materials, and a fire burned for three days. But the scant news coverage largely ceased on March 5, the day when China's ceremonial legislative body _ the National People's Congress _ opened in Beijing for its annual meeting.

There is no official explanation for the lack of attention to the tunnel crash, but it would be consistent with China's heightened efforts to ensure social stability when the congress was in session by playing down what the authorities deem as negative news.

Also, senior government officials were in Beijing for the congress, leaving a temporary leadership vacuum in local governments.

Xinhua News Agency said two tankers loaded with the flammable methanol collided inside the Yanhou Tunnel on a highway in Shaanxi province, causing a blast and setting fire to coal trucks in the traffic.

The March 5 report by Xinhua said 13 people were dead, another 11 injured, and 42 vehicles destroyed in the fire that burned more than 1,500 tons of coal over 73 hours. An update on Tuesday said the death toll had increased from 13 to 16.

Xinhua said it had been extremely challenging to identify victims, because many bodies were carbonized in the blaze.

The official microblog by a local highway battalion made no mention of the deadly crash but on March 5 posted a notice by the provincial government that bans hazardous chemicals from all highways in the province for one year. (AP)