The Russian space agency says the country's first lunar probe in nearly half a century failed when the unmanned spacecraft crashed into the Moon.

Roscosmos said on Sunday that the results of preliminary analysis indicate that the Luna-25 "moved into an unpredictable orbit and ceased to exist" as a result of a collision with the surface of the Moon.

The agency also said that a special commission had been set up to investigate the reasons behind the loss of the craft.

Russia launched the Luna-25 on August 11. Space scientists lost contact with the spacecraft after they tried to shunt it into a pre-landing orbit on Saturday.

The Luna-25 was the first Russian lunar probe after the Luna-24 returned soil samples from the Moon in 1976 during the Soviet era.

The Luna-25 was expected to make the world's first attempt to land near the Moon's south pole as early as August 21. It would then spend a year exploring for deposits of water and other resources.

Meanwhile, India is set to attempt a lunar landing soon with its Chandrayaan-3 probe.

The Indian Space Research Organization, or ISRO, said on Sunday that the final deboosting operation was successfully completed to prepare for a landing.