An international police team abandoned its attempt to reach the crash site of a Malaysia Airlines plane for a second day running Monday as clashes raged in a town on the road to the area.
With government troops intensifying their push to claw back more territory from pro-Russian separatist rebels, the death toll is mounting steadily. The United Nations released new figures Monday showing that more than 1,100 people have died in more than four months of fighting.
The international delegation of Australian and Dutch police and forensic experts stopped Monday in Shakhtarsk, a town around 20 miles (30 kilometers) from the fields where the Boeing 777 was brought down.
Sounds of regular shelling could be heard from Shakhtarsk and residents were seen fleeing town in cars.
Associated Press reporters saw a high-rise apartment block in Shakhtarsk being hit by at least two rounds of artillery.
The mandate of the police team is to secure the currently rebel-controlled area so that comprehensive investigations can begin and any remaining bodies can be recovered.
Their visit was canceled Sunday amid safety concerns.
Ukraine has accused rebels of tampering with evidence and trying to cover up their alleged role in bringing the Malaysia Airlines plane down with an anti-aircraft missile.
Separatist officials have staunchly denied responsibility for shooting down the airliner and killing all 298 people onboard.
A Ukrainian security spokesman said Monday that data from the recovered flight recorders shows Malaysia Airlines Flight 17 crashed due to a massive, explosive loss of pressure after being punctured multiple times by shrapnel. Andrei Lysenko said the plane suffered "massive explosive decompression" after it was hit by fragments he said came from a missile.
The data recorders were sent to experts in Britain for examination.
In their campaign to wrest control over more territory from separatist forces, Ukraine's army has deployed a growing amount of heavy weaponry. Rebels have also been able to secure large quantities of powerful weapons, much of which the United States and Ukraine maintain is being supplied by Russia.
Moscow dismisses those charges.
While Russia and Ukraine trade accusations, the death toll has been mounting swiftly.
The U.N. High Commissioner for Human Rights said in a report out Monday that at least 1,129 people have been killed between mid-April, when fighting began, and July 26. The report said at least 3,442 people had been wounded and more than 100,000 people had left their homes. A U.N. report from mid-June put the death toll at 356.
At least eight civilians were killed by fighting and shelling in two cities held by separatist militants overnight Sunday, officials in the rebellion-wracked region said.
Authorities in Luhansk said that five people were killed and 15 injured by overnight artillery strikes. Three were killed in Donetsk as a result of clashes, the city's government said.
Rebels accuse government troops of deploying artillery against residential areas. Authorities deny that charge, but also complain of insurgents using apartment blocks as firing positions.
The U.N. said in its report that rebel groups continue to "abduct, detain, torture and execute people kept as hostages in order to intimidate" the population in the east. It said rule of law had collapsed in the rebel-held areas and that 812 people had been abducted in the Donetsk and Luhansk regions since mid-April.
It also reported heavy damage to electrical, water and sewage plants and estimated the costs of rebuilding at $750 million - money the government would have to find by cutting social programs.
The U.S. State Department on Sunday released satellite images that it says back up its claims that rockets have been fired from Russia into eastern Ukraine and heavy artillery for separatists has also crossed the border.
Russian Foreign Minister Sergey Lavrov dismissed the claims Monday during a televised press conference, asking "why it took 10 days" before the U.S. released the images.
A four-page document released by the State Department appears to show blast marks from where rockets were launched and craters where they landed. Officials said the images, sourced from the U.S. Director of National Intelligence, show heavy weapons fired between July 21 and July 26 - after the July 17 downing of Malaysia Airlines Flight 17.
The images could not be independently verified by The Associated Press.