Russia has grounded its Soyuz rockets after a space ship carrying tonnes of cargo for the International Space Station (ISS) crashed into Siberia shortly after blast-off, an official said Thursday. The failed launch of the unmanned Progress capsule was a spectacular blow for Russia which had proudly become the sole nation capable of transporting humans to the ISS after the withdrawal of the US space shuttle in July. Emergency services blocked access to the site of the crash in the Altai region of Siberia, state television said, amid fears the space freighter could have dumped highly-toxic fuel in the area.