George and Angela Dyczynski sit on a piece of wreckage of the downed Malaysia Airlines Flight MH17, during their visit to the crash site near the village of Hrabove (Grabovo), in Donetsk region July 26, 2014. According to local media, the Perth-based couple's daughter Fatima was aboard the Malaysia Airlines plane en route from Amsterdam to Kuala Lumpur when it was brought down in eastern Ukraine, where separatists are battling government forces, on July 17. [Photo/Agencies]

Malaysian Airlines Flight 17 was shot down with a surface-to-air missile over a part of eastern Ukraine controlled by pro-Russian separatists on July 17, killing all 298 people on board. US and Ukrainian officials say it was shot down by a missile from rebel territory, most likely by mistake.

Ten days after the disaster, a full-fledged investigation still has not begun at the crash site, with some bodies still unrecovered and the site forensically compromised. Concerns about the integrity of the site were raised further when a couple that had flown from their home in Perth, Australia, visited the site Saturday outside the village of Hrabove and even sat on part of plane's wreckage.

It remained unclear when the forensic experts from the Netherlands and Australia would be able to begin their work at the site.

Alexander Hug, the deputy head of a monitoring team from the Organization for Security and Cooperation in Europe, said it was too dangerous for the unarmed officers to travel there from their current location in Donetsk.

"We reassess the situation continuously and we will start to redeploy tomorrow morning back to the site if the situation changes," Hug said.

Australian prime minister Tony Abbott had said earlier Sunday that unarmed Australian police would be part of the Dutch-led police force to secure the area and help recover victims' remains.

Abbott said that by using unarmed police, Ukraine's Parliament will not need to ratify the deployment as it would if the security force were to be armed.

"This is a risky mission. There's no doubt about that," Abbott told reporters. "But all the professional advice that I have is that the safest way to conduct it is unarmed, as part of a police-led humanitarian mission," he said.

Malaysian Prime Minister Najib Razak said in a statement that his country would send dozens of police and that his country had received assurances from pro-Russia separatists that they would provide protection for investigators.

Flights from Ukraine to the Netherlands have taken 227 coffins containing victims of the plane disaster. Officials say the exact number of people held in the coffins still needs to be determined by forensic experts in the Netherlands.

The Malaysia Airlines disaster prompted some expectations in the West that Russia would scale back its involvement in the uprising in Ukraine's east, but the opposite seems to be the case.

In addition to producing evidence that rockets have been fired into Ukraine from Russia, the United States has said it has seen powerful rocket systems moving closer to the border.

In Warsaw, about 250 people marched through the city to protest what they called the "terror" imposed by Russian President Vladimir Putin in Ukraine. Some of the demonstrators carried Ukrainian flags, and there were banners that proclaimed "Putin is a Sponsor of Terror" and "Europe, Stop Just Talking. Start Taking Action! Stop Terror in Ukraine."