DONETSK, Ukraine - Fighting between government forces and pro-Russian rebels left at least 10 civilians dead in eastern Ukraine on Sunday as an international probe at the crash site of downed flight MH17 made headway.
The deputy mayor in the encircled insurgent stronghold of Donetsk told AFP that shooting in a residential suburb had killed six civilians and injured 13, the latest victims of more than three months of civil war that has claimed at least 1,150 lives.
Local authorities in the second-largest separatist bastion of Lugansk said shelling had left three dead and eight injured, while the city council in the frontline rebel base of Gorlivka reported one dead and 16 hurt in clashes there.
Ukraine's military said its positions in the region continued to come under heavy bombardment, including shellfire allegedly from across the porous border with former Soviet master Russia.
Government forces have made major gains over the past month and say they are getting close to cutting off fighters in Donetsk from the Russian border and their comrades in Lugansk.
Kiev has promised to stamp out the insurgency in the near future but analysts warn the fighting could drag on as rebels have holed up in major cities and pledged to battle to the death.
A top rebel chief admitted that Donetsk was in a state of "siege" and said fighters were trying to battle past a government blockade.
"Our guys are dying heroically in efforts to break through," said deputy prime minister of the self-styled Donetsk People's republic Vladimir Antyufeev.
And it is civilians in the blighted region who are bearing the brunt of the violence.
In the face of the punishing government blockade, the mayor of Lugansk, a city of some 420,000, is warning of a looming "humanitarian catastrophe" as electricity has failed and water and fuel supplies have run out.
The United Nations says more than 100,000 people have fled the fighting for other parts of Ukraine, while Russia claims another half a million have crossed the border in search of refuge.
One zone searched
The latest violence came as scores of Dutch and Australian police investigators completed a third day trawling through the vast MH17 debris field for more remains of the 298 people killed when the Malaysian passenger jet was blown out of the sky over separatist territory almost three weeks ago.
After days of fierce fighting prevented experts from reaching the scene of the disaster, the Dutch-led probe has now bulked up to nearly full strength with sniffer dogs and refrigerated ambulance vans brought in as they work to make up for lost time.
"We have already searched one of the five zones that we have divided the crash site into," said Pieter-Jaap Aalbersberg, head of the Dutch police mission.
Search crews continue to turn up body parts and personal belongings scattered across some 20 square kilometres (eight square miles), and those leading the probe say it could take some three more weeks. A total of 220 sets of remains have already been taken to The Netherlands for identification.
Another plane carrying an unspecified number of remains will fly out of the government-held city of Kharkiv on Monday.
Aalbersberg told journalists in the city that a train wagon carrying victims' possessions was currently stuck at a rebel-held train station.
The United States accuses insurgents of downing MH17 on July 17 with a surface-to-air missile likely supplied by Russia, while Moscow and the rebels blame the Ukrainian military.
International shock waves from the crisis continue to reverberate with tensions between Russia and the West at their highest since the Cold War.
The United States and European Union have hit Moscow with the toughest sanctions seen since the collapse of the Soviet Union over the Kremlin's alleged arming and instigation of the separatist rebellion.
One target was Russian airline Aeroflot's low-cost domestic airline Dobrolet, which was forced to cancel all its flights from Monday because of scrapped leasing deals for Boeing aircraft.
According to a German newspaper report Monday, Berlin has decided to scrap a major deal to provide a fully-equipped training camp to Russian forces due to the ongoing crisis in Ukraine.
But the punishing measures are yet to quell the fighting and US President Barack Obama on Friday expressed "deep concerns" about Moscow's increased support for the insurgents in a phone call with Russian counterpart Vladimir Putin.
Russia, which risks seeing its fragile economy slip into recession because of the sanctions, has warned that measures will backfire on Western interests.
Some EU diplomats have warned that the sanctions could actually embolden Putin by convincing him he has nothing to lose by going all-in over the Ukraine crisis.
NATO chief Anders Fogh Rasmussen said in an interview published Sunday that the alliance would draw up new defence plans in the face of "Russia's aggression" against Ukraine, urging members to up their military spending.