At least 20 people were killed and four seriously injured in a traffic accident in Russia's central Vladimir region, local media reported on Thursday.

A bus full of passengers collided with a truck on a highway some 124 km away from Moscow, Russian officials said.

The bus caught fire after the crash and the injured have been rushed to the local hospital, officials said.

An investigation is underway but the cause of the accident remains unclear.

(Xinhua News Agency March 26, 2009)