About 100 people died in an overnight train accident in central Congo in which seven cars overturned, officials in the Central African country said Thursday.

Seven cars overturned in the accident, while another was leaning part way off the track Thursday, said Medard Ilunga, head of Congo's state railway agency.

The train's locomotive stopped responding to controls as it traveled between the cities of Ilebo and Kananga late Wednesday, leaving the conductor without a way to brake, he said.

Around 100 people died and scores of others wounded in the accident, about 100 miles northwest of Kananga — the capital of Congo's Kasai Occidental province, Ilunga said. He said the accident occurred just before midnight and the conductor was able to detach the locomotive to go for help after the accident.

The U.N. has sent helicopters with doctors, nurses and medical equipment to the site to help military and civilian authorities with the relief effort, said Kemal Saiki, spokesman for the United Nation's peacekeeping operation in the Central African nation.

The United Nations has a large, established force in Congo to help the embattled country in its transition to democracy following decades of war and corrupt dictatorship.

Roads and rail are notoriously dilapidated in vast Congo — a country the size of Western Europe. Most of Congo's railroads were built more than 100 years ago, when the country was a Belgian colony.

Government spokesman Toussaint Tshilombo Send said the president had sent a mission to the site to help in the rescue effort and comfort the families. He added that an investigation will be mounted into the accident.