A high-speed express train traveling from Leningrad to Moscow derailed halfway between the two cities and caught fire, killing at least 17 people and injuring 106 others, the official Tass news agency said Wednesday.

The news agency said initial firefighting efforts were delayed, but rescue teams rushed to the site of the Tuesday night accident, and special trains took 557 survivors to Moscow.The Central Committee of the Soviet Communist Party expressed its condolences to the families and relatives of those who died in the accident, usually a sign of a high number of casualties.

Tass did not disclose the number of people on the train, but the figure of 557 survivors, together with the 106 injured and 17 dead, would indicate the train carried almost 700 people.