Prague - Two workers were killed and one injured on Thursday in a blast in a coking plant in the north-eastern Czech Republic, the plant owner said.

The men, aged 51 and 55, were doing maintenance work on an ammonia water tank which exploded for an unknown reason, said company spokesman Vladislav Sobol.

Another worker suffered a broken hand which was believed to have been hit by a tank shard, he said.

The cause of the blast, which was not immediately known, is under police investigation.

The coking plant is owned by Dutch-registered New World Resources coal miner. The group, listed on the London, Warsaw and Prague stock exchanges, is controlled by Czech financier Zdenek Bakala. (dpa)