A team of 70 Dutch and Australian forensic experts has finally got to work at the site of the flight MH17 crash in east Ukraine.
They arrived in a convoy with Organization for Security and Co-operation in Europe (OSCE) monitors and began setting up a base in a farm.
Australia believes that around 80 bodies remain at the site.
Fighting still rages in the region, with 10 Ukrainian soldiers killed in a rebel ambush on Thursday.
The fighting had previously prevented the investigators reaching the area where the Malaysia Airlines jet came down on 17 July with the loss of all 298 passengers and crew.
But after Ukraine's military declared a unilateral one-day suspension of operations against the rebels in Donetsk region on Thursday, an exploratory visit was made, followed up by the full deployment on Friday.
OSCE convoy w/largest-ever group Dutch/Australia experts reaches #MH17 site. 60+ experts, SMMU monitors. Recovery works starts immediately
— СММ ОБСЄ в Україні (@OSCE_SMM) August 1, 2014
It is now unclear whether Ukraine's army or separatist forces control the site, as fighting continues nearby, the BBC's Tom, Burridge reports from Kharkiv.
On Thursday a rebel delegation held talks with officials from Ukraine, Russia and the OSCE in Minsk, capital of Belarus. The talks are to resume next week, the OSCE said in a statement.
'STENCH OF DEATH'
The investigators travelled in 16 vehicles to the crash site, outside the village of Grabove, AP news agency reports.
By midday, they had begun setting up base at a chicken farm while artillery fire could be heard periodically somewhere in the distance, AP says.
In a tweet, the OSCE said the investigators had been bolstered by "new assets", an apparent reference to two vans marked with red crosses.
Pieter-Jaap Aalbersberg, head of the investigation at the crash scene, said on the Dutch justice ministry's website: "If human remains are found during the search, they will be recovered instantly."
It is believed that remains and debris were scattered over a 35 sq km (13.5 sq mile) of countryside, to the east of the rebel-held city of Donetsk.
Regional OSCE spokesman Michael Bociurkiw, who visited the site previously, said that despite reports of tampering with evidence, it looked much the same as when his team had last seen it, nearly a week ago.
"Everything is still more or less the way we saw it," he told Boston's NPR news station by phone.
"In some ways it is remarkable in the sense that, two weeks into this, there are many parts that haven't been touched," he said, speaking on Thursday.
"The stench of death is still there," he added. "It is very hot today."
Most of the bodies were recovered earlier by local search tea and were flown to the Netherlands, where most of the victi came from.
More than 1,500 people are believed to have been killed in the conflict which erupted in east Ukraine in April, after separatists declared independence from the new government in Kiev.
Russia, which annexed Ukraine's Crimea region in March, has been accused of arming the rebels and has been targeted by US and EU sanctions.
'OVERWHELMING ENEMY FORCES'
The rebels say they destroyed more than 30 vehicles in the ambush while unverified video shows bodies around a burning vehicle.
Vladyslav Seleznyov, spokesman for Ukraine's "anti-terrorist operation", said a unit of paratroopers had been ambushed on Thursday while moving to a new position.
Paratroopers had fought back and inflicted "significant losses" on their attackers, he said.
Ukrainian military spokesman Oleksiy Dmytrashkivsky confirmed that 10 soldiers had been killed while a further four bodies had yet to be identified.
A Ukrainian TV station, Channel 112, said the attack had happened during the night and 20 paratroopers had been killed.
Meanwhile, the Donetsk rebels' news agency said on Twitter that an "enemy" column had been "repulsed" and three soldiers from Ukraine's 25th Air Mobile Brigade had been taken prisoner.
Graphic amateur video published on YouTube, and dated 31 July, shows a burning military vehicle with charred and mangled bodies scattered nearby. The dead soldiers are said to be from the 25th Brigade.