Media playback is unsupported on your device Media caption The rocket exploded over the Russian-leased Baikonur launch facility in Kazakhstan

An unmanned Russian Proton-M rocket has crashed just seconds after its launch from the Russian Baikonur facility in Kazakhstan.

Dramatic video footage broadcast by Russian TV shows the rocket break up before exploding into a fireball over the Baikonur cosmodrome.

Russia's Interfax news agency reported that up to 500 tonnes of poisonous rocket fuel may have been released and contaminated the crash site.

There were no reported injuries.

The rocket was carrying three satellites for Russia's Glonass (global) navigation satellite system.

It is not yet clear what caused the accident.

It is not the first incident involving a Proton-M rocket, according to the BBC's Steve Rosenberg in Moscow.

A similar rocket crashed shortly after it was launched six years ago, and in 2010 another rocket failed to put three navigation satellites into orbit.