Reports of execution-style killings, mass graves, and torture in eastern Ukraine have been grossly "misreported" and possibly "exaggerated," according to a new report by Amnesty International.

The report — titled _Summary Killing During the Conflict in Eastern Ukraine —_details a series of interviews conducted by human rights investigators in eastern Ukraine's Donbass region over late August and September. It says both Ukrainian forces and pro-Russian separatists have have manufactured or misrepresented the death and torture of civilians.

"There is no doubt that summary killings and atrocities are being committed by both pro-Russia separatists and pro-Kiev forces in eastern Ukraine, but is difficult to get an accurate sense of the scale of these abuses," John Dalhuisen, Amnesty's Europe and Central Asia director, said in a statement. "It is likely that many have not yet been exposed and that others have been deliberately misrecorded."

Casualties and chaos continue to mount in the country's contested east, where witnesses say Ukrainian forces and pro-Russia rebels still clash on a near-daily basis despite a fragile ceasefire agreement signed by the parties on September 5.

UN figures estimate at least 3,600 people have been killed and more than 8,700 wounded in the region since mid-April, when tensions flared up in the region following Russia's annexation of Crimea. Some 331 people have died in the fighting since the ceasefire took hold.

The human rights situation in eastern Ukraine is deteriorating rapidly amid reports of constant shelling, gunfire, and reprisal attacks, the UN said in its own bi-annual report released this month. The fighting has disrupted the lives of millions of residents, whose homes, businesses, schools and hospitals have been destroyed.

But Amnesty's report, which also details the extra-judicial murders of local activists and detainees, suggests both sides are exaggerating the scale of abuses and encouraging speculation for propaganda purposes, rather than "investigating and eliminating execution-style killings by forces they control."

Dalhuisen said some of the more "shocking cases" reported were "hugely exaggerated," particularly by Russian media. These include Russian reports last month involving the alleged unearthing of some 400 murdered civilians, including a pregnant woman, in mass graves outside the villages of Komunar and Nyzhnya Krynka in Ukraine's Donetsk region.

Amnesty's monitors, who visited the area late September, found only evidence that four local men had been executed by suspected pro-Kiev forces and buried in two graves outside Komunar, while five corpses, later identified as belonging to separatist fighters who died in battle, were also uncovered in a nearby grave, according to the report.

Dalhuisen said the monitors found no "compelling evidence of mass killings or graves," but rather "isolated incidents of summary executions that in some cases constitute war crimes."

"The reality behind Russian claims of 'mass graves' in Nyzhnya Krynka is grisly enough… These must now be investigated thoroughly," Dalhuisen said. The reports show "the extent to which accusations of abuses are being inflated, particularly by the Russian authorities, in the parallel propaganda war."

The report was released over the weekend as Ukrainian President Petro Poroshenko and Russian President Vladimir Putin failed to make progress in talks to end the months-long crisis at an EU summit held in Italy.

The leaders did make headway in striking a deal for Russia to supply Ukraine with natural gas during the freezing winter months. Moscow had previously cut off gas supplies to Ukraine earlier in June over a contested unpaid debt, estimated in the billions.

Meanwhile, the Donetsk mayor's office released a statement Sunday saying four people were killed and nine wounded by shrapnel in sustained heavy shelling and gunfire that could be heard across the city.

Homes, shops, a chemical factory, and a school were also damaged in the crossfire, the Mayor's office said, while a power station was set alight following a blast, affecting local power supply.