Mende Omalanga, the minister of communications, said that the tanker had overturned as it was trying to overtake a bus on a dirt road through the village of Sange, in South Kivu province, 60 miles south of the city of Bukavu.

He said that the driver survived the accident, and that the initial spill was ignited by the cigarette of a man trying to salvage some of the fuel in a tin can.

A number of the injured were being treated in surrounding villages, but most were sent to the nearby town of Uvira, he said. The UN mission in the country said that the fire was still burning yesterday afternoon, and that the UN had provided ambulances and three helicopters to assist with rescue efforts.

Some 35 people had been airlifted to hospitals in Uvira and Bukavu. The UN said that 223 people had been killed and at least 110 injured, but that the numbers were expected to rise as the fire continued to burn.

"What is certain is that the toll will get higher," a spokesman said, adding that the search was continuing "for more charred bodies".

The truck, owned by a company called Ginki, had been delivering to the area from neighbouring Tanzania. One police officer based in Bukavu claimed that the accident was caused by the tanker's "excessive speed". The officer, who asked not to be named, said many of those who surrounded the vehicle before it exploded were children, and that the village – home to many Congolese soldiers and their families –was now "in total mourning".

The International Committee of the Red Cross is taking medicine and body bags to the village and preparing to fly the wounded to hospital. James Reynolds, deputy head of the ICRC in the area, said: "It is a small village. When the truck turned over a lot of people gathered round. It then caught fire and spread through the village."

Katrina Manson, a journalist with the Reuters news agency in the country, said that once the fuel started leaking "it ran absolutely everywhere."

Roads in the area are notoriously bad after years of war and neglect in the vast central African nation. The population of Sange has more than doubled in the past year to about 40,000 as the result of an influx of refugees fleeing the Lord's Resistance Army, a sectarian militant group, to the north and ongoing sporadic fighting between government forces and Rwandan militias.

The refugees have been taken in by local people and the village has a high concentration of orphans.

Sange was the subject of a remarkable project by celebrity photographer Rankin, who visited the village last year and produced a book, We Are Congo, with images of the residents for Oxfam.

"It's a terrible scene. There are lots of dead bodies on the streets. The population is in terrible shock – no one is crying or speaking," said Jean-Claude Kibala, South Kivu's vice-governor. "We are trying to see how we can co-ordinate [with the UN] to manage the situation."