He said bodies of the dead and the injured had been taken to morgues and hospitals in Pointe Noire.

Relatives of the dead and injured filled the railway stations at Pointe Noire and Dolisie, anxious for news of their loved ones, witnesses in the cities said.

Few details were available of the accident, however, from the rail company or the government.

The 510km CFCO line is the main link between the capital Brazzaville and Pointe-Noire on the Atlantic and mainly follows the Congo river.

Past deaths

It was built between 1921 and 1934 during French colonial rule and thousands of Africans are said to have died making the railway.

grim history
  Congo-Ocean Railway
  Built between 1921 and 1934 by French
  At least 17,000 people died building the railway
  The line was closed in the late 1990s during the country's civil war
   At least 50 people were killed in a 2001 accident
  10 died in 2003 accident when a train derailed
  In 2007, about 100 people died in an accident

At least 50 people were killed on the same line in 2001, many of them burned to death, when two trains collided at Mvougounti around 75km east of Pointe Noire.

In August 2007, about 100 people died when a passenger train slammed into a freight train, also at Mvougounti.

The lack of roads and the dysfunctional railway system between the main towns make travel difficult and contribute to the high cost of food and imported goods in the capital and throughout neighbouring land-locked nations.

Chinese engineers started work late last year on a $500m road linking the oil hub of Pointe Noire with Brazzaville, a project that will involve crossing equatorial forests and steep mountains.

Congo, which has long exported millions of barrels of oil but remains mostly poor and suffers from poor infrastructure, is seeking to diversify its economy as oil reserves wind down.