At least 57 people have been killed after a passenger train went off the rails in the Democratic Republic of Congo.

The latest figure from the government raises an earlier death toll as difficult rescue operations continue in the remote area.

The newly purchased engine flew off the rails as it went around a bend in a swampy area in the southeast of the country.

The crash caused 15 of the train's 19 cars to overturn.

The official death toll was first given as 37 people, but government spokesman Lambert Mende later gave an updated toll of 57.

Other sources put the figure even higher.

A journalist at the scene said a local official had given a toll of about 60 dead and 86 wounded.

Local human rights activist Timothee Mbuya said that "so far at least 100 bodies have been taken from the train and buried, because there's no morgue".

The train was travelling north from the town of Kamina in the southern province of Katanga to Mwene-Ditu in the diamond-mining province of Kasai-Oriental.

Witnesses said it was carrying hundreds of passengers both in and on its cars, many of whom had paid an illegal reduced fare to ride the train without a proper ticket.