Leaders of Russia and Germany said on Saturday that the Malaysian plane crash in eastern Ukraine should be investigated by the International Civil Aviation Organization (ICAO)thoroughly and impartially.

"Both parties emphasized the importance of a thorough and impartial investigation into all circumstances of the accident," the Kremlin press service said, citing a telephone conversation between President Vladimir Putin and German Chancellor Angela Merkel.

The probe should be conducted by the ICAO and involve all parties concerned, it said, adding Merkel "positively" took Russia's willingness to dispatch representatives to assist with the investigation.

The two leaders said bloodshed must be stopped immediately in eastern Ukraine, and that contact group talks involving representatives from conflict-hit regions should be resumed.

They also agreed that it "would be of fundamental importance" to implement Russia's initiative on the presence of Organization for Security and Cooperation in Europe monitors at two checkpoints on the Russian-Ukrainian border.

A Malaysia Airlines Boeing 777 plane crashed Thursday in restive eastern Ukraine near the Russian border, killing all 298 people on board.

The Ukrainian government and insurgents in the country's east have traded accusations, with both sides claiming to have evidence.

Earlier on Saturday, Ukraine's intelligence chief Valentin Nalivaichenko said the government and insurgents had agreed to form a 20-km "security zone" around the crash site to facilitate the investigation and other humanitarian obligations.