An unmanned Russian Proton-M carrier rocket exploded on takeoff at the Baikonur cosmodrome in Kazakhstan, in images broadcast live on national television.
Spectacular footage showed the rocket veering off its trajectory just seconds after its 6.38 am (0238 GMT) launch, before erupting into a ball of flames and releasing highly toxic rocket fuel into the air.
The Russian space agency Roskosmos, citing preliminary information, said the accident caused no damage or casualties.
The rocket then exploded, sending plumes of black smoke into the morning sky.
The rocket was supposed to take three Glonass-M satellites into space.
The agency said that during the accident, which took place 10-15 seconds after takeoff, toxic rocket fuel was released into the air.
A Roskosmos spokesman could not immediately say whether people living near the crash site were being evacuated.
Russia has suffered several recent setbacks in its space programme, notably losing expensive satellites and an unmanned supply ship to the International Space Station.