MOSCOW (dpa) - The Mars probe launched by the Russia space agency in early November is to come crashing down to earth over the next few days, bringing with it some highly toxic fuel and a tiny amount of radioactive cobalt.

Roskosmos is banking on most of the Phobos-Grunt, as the failed mission is called, burning up as it re-enters the earth's atmosphere on Sunday - but large chunks of its 13.5 tonnes are certain to survive the uncontrolled and fiery descent.

Current predictions are for the surviving bits of the probe to splash down into the Indian Ocean, but as previous uncontrolled descents have shown, this cannot be guaranteed.

The Phobos-Grunt was stuck in ''parking orbit'' after its November 9 launch from Baikonur Cosmodrome in Kazakhstan, circling the earth after its engines refused to fire to start the long journey to the Red Planet. The 150-million-dollar project had been intended to boost the prestige of the Russian space programme, 15 years after the country's last interplanetary mission.

Russia also aimed to stake its claim following recent successes scored by China in its space programme and the announcement of plans by the United States to embark on a new Mars programme.