The toll from a powerful explosion in China rose to 14 dead and 147 injured Tuesday, state media said, as three suspects were arrested and admitted to illegally storing explosives.

Monday's blast in Xinmin, in the northern province of Shaanxi, tore through five prefabricated buildings, destroying or damaging 58 others, the official Xinhua news agency said.

Authorities on Tuesday censored discussion of the incident online.

An initial investigation found the incident was caused by illegally stored explosives, state broadcaster CCTV said on its website late Tuesday, adding that three people had been arrested.

"During the investigation, the suspects confessed to illegally producing and storing explosives," it said.

Pictures showed widespread damage, with windows blown out of buildings, a crater in the street, and bloodied victims lying on the ground.

Rescue efforts had concluded by Tuesday morning, and more than 100 of the injured were still hospitalised, Xinhua said, citing local authorities.

The explosion comes at a time of heightened vigilance for the ruling Communist Party, which holding a high-level meeting in Beijing, the "Sixth Plenum".

Outraged social media users said that there were comparatively few reports on the incident available online, and others had been deleted, with comments on many platforms disabled.

"They've closed off discussion of the incident and don't dare reveal the numbers of casualties and deaths," wrote one incensed user. "Such a big incident, and they're preparing to quash it under pressure."

Another cried: "The one-party dictatorship that controls the throne is only interested in the good of the party, not of the people! Where is China's future?"

Industrial accidents are common in China, where safely regulations are often flouted.

Giant explosions at a chemical storage facility in the northern port of Tianjin last year killed at least 165 people, sending a monumental fireball skyward and mangling structures kilometres away.