ACCIDENT investigators detained two Moscow Metro workers today in the wake of Tuesday’s deadly rush-hour derailment that killed 22 people and injured 136 others.

More than 1,100 people were evacuated after a train was unseated between two stations in western Moscow.

Eight people were still in a critical condition and 40 others had serious injuries, said Moscow Mayor Sergei Sobyanin yesterday.

The two detained workers are a senior Moscow track foreman and his assistant.

Investigators said that a new rail switch at the point where the train left the tracks had not been properly installed during repairs in May and was attached to the rail only by a single 3-millimetre wire. 

A new line is under construction nearby and the switch was to direct trains to a new tunnel once the line is launched.

Unspecified charges are being prepared against the two men, said investigating committee spokesman Vladimir Markin.

The affected line will remain suspended until tomorrow morning.