Ukrainian President Petro Poroshenko has ordered Ukrainian forces to stop military actions and operations within a 40-km diameter of the Malaysian plane crash site.

"I have given the order: right away, Ukrainian servicemen must not hold operations and must not open fire within the 40-km diameter of the site of the tragedy," Poroshenko told reporters while visiting the Malaysian embassy in Kyiv.

Looting, destroying evidence and "impeding activities of the Ukrainian investigative committee and committee formed by the International Civil Aviation Association (ICAO)" are occurring at the crash site, Poroshenko said.

Meanwhile, First Deputy Prime Minister of the self-proclaimed Donetsk People's Republic (DPR) Andriy Purhin said when commenting on Poroshenko's statement on the 40-km zone at the crash site that "The DPR militia guaranteed security at the site from day one after the crash."

The militia "did everything in order to guarantee the safe work of experts and international specialists at the plane crash site," Purhin said.

"Nevertheless, too many Ukrainian law enforcers are near the scene of the tragedy. I am afraid that it will be impossible to avoid local clashes. Provocations by the Ukrainian party are possible," Purhin told Interfax on Monday.