Kazakhstan's Emergencies Ministry said the decision was made after experts determined that the area where the rocket fell is polluted with heptyl, a highly toxic fuel. The ministry said heptyl concentration in the scarcely populated territory where the accident occurred is 1,000 times higher than the maximum admissible levels.
Environmentalists say heptyl is a highly poisonous substance widely used in the Russian space industry.
The RS-20 (Dnyepr) rocket crashed 73 seconds after taking off from the Baikonur launchpad. It was carrying several satellites, including what should have been Belarus' first-ever satellite.
The cause of the accident is unknown. Preliminary reports suggest the rocket crashed after its third section detached.
(Kazakhstan Today, Interfax-Kazakhstan)