A passenger train collided with a goods train carrying inflammable material near the town of Dete, on a railway line linking the southern city of Bulawayo to the western resort of Victoria Falls. A fierce fire broke out, and some of the dead were burnt beyond recognition.
State radio said 30 bodies had been recovered from the wreckage, and many more passengers were being ferried to hospital facilities at the nearby town of Hwange.
Hours after the crash at 0300 local time (0100 GMT), rescuers were still trying to free people trapped in the mangled wreckage, and there were fears that the death toll would rise.
Zimbabwe's Transport Minister Witness Mangwende - who visited the scene of the crash - blamed the accident on human error. Mr Mangwende said a mistake in track signals had sent the two trains onto the same track. President Robert Mugabe sent his condolences to the relatives of the dead.
String of crashes
The passenger train was believed to have carried 1,100 people in 13 coaches, 11 of which were destroyed in the crash, which was apparently head-on.
The BBC's Hilary Andersson says passenger trains in Zimbabwe have become increasingly overcrowded in recent months due to severe fuel shortages. She says the National Railways of Zimbabwe (NRZ) has found it difficult to import spare parts and maintenance equipment for its railway system recently, because of the lack of hard currency in the country.
Saturday's accident is the latest in a string of crashes involving trains in Zimbabwe.
Last month, five people were killed and more than 100 injured when a goods train ploughed into a bus in Harare.
Last October, 22 people were injured when a passenger train on its way to Victoria Falls derailed near Hwange after colliding with an elephant.
Our correspondent says the latest incident will not make it any easier for Zimbabwe to improve its image as a safe and attractive tourist destination prior to the Cricket World Cup, which starts later this month.
Source: 40 die in Zimbabwe train crash (02/02/03)