Windows were shattered and homes shaken in Donetsk after a huge blast rocked the vicinity of a city chemical plant which was under rebel control. Kiev and the militants accuse each other of causing the blast.

The powerful explosion took place at 10:50pm local time on Sunday. Local militia reported that a military chemical plant DKZHI was the target of Kiev’s artillery shelling.

Witnesses saw the sky lit up by the explosion, some nearby living residents had their windows broken by the blast’s shockwave and many others felt the ground shake, RIA Novosti reported. Even those living in nearby towns said they felt the tremor.

“The center of the blast was near DKZHI,” co-chairman of the anti-Kiev People’s Front Konstantin Dolgov said on his Facebook page. The factory is known for producing chemical products used for industrial explosives, ammunition and equipment artillery bombs. This is not the first time the plant has been the target of a Kiev attack. It was also hit with artillery rockets in September and November.

The militia forces would not immediately confirm if there were casualties, either among militiamen or civilians. But they said the fire, which started after the explosion, poses no threat of a chemical spill, which is a cause of great concern at the plant, as it handles toxic compounds in producing explosives.

“The fire has been contained. There is not threat of chemical spill… Most likely it was a high-caliber artillery shell,” said an official from the Donetsk People's Republic.

The spokesman for Kiev's Anti-Terrorist Operation said that rebels were at fault for the accident.

"This was caused by a dropped cigarette butt," Andrey Lysenko told the media on Monday.

"Accidents often happen in factories where no one is responsible for fire safety. Well, it's chaos, and they are barbarians."

Not all pro-Kiev officials agreed.

The Ukrainian military deployed a Smerch (the BM-30 Tornado) multiple rocket system to shell the area in the city, Boris Filatov, former deputy head of the industrial Dnepropetrovsk Region and a member of the Ukrainian parliament (Verkhovna Rada), said on his Facebook page.

According to Filatov, the men who fired the missiles “do not know what they hit because they were shooting based on coordinates.”

Earlier, Ukrainian far-right politician and paramilitary commander Dmitry Yarosh, who is involved in the Kiev military action in southeastern Ukraine, confirmed on his Facebook page that the explosion was caused by Ukrainian artillery.

Yarosh, who is wanted by Interpol on charges of inciting terrorism, was elected to the Rada in October 2014. He played a key role in the protests on Maidan (Kiev’s Independence Square), which led to the toppling of Viktor Yanukovich’s government earlier that year. Back in May, the Right Sector leader received less than 1 percent of the vote in Ukraine’s presidential election.

Meanwhile, the situation in southeastern Ukraine has been rapidly worsening since January 18, when Ukrainian troops have launched a massive assault on militia-held territories after an order from Kiev.

Shelling of the rebel-controlled towns has been witnessed on a daily basis, including the city of Donetsk, with both sides blaming each other for violence. Meanwhile, the indiscriminate shelling of residential areas by Kiev, at times with internationally-prohibited arms, has even been confirmed by the Ukrainian government’s strongest supporter – Washington.

John McCain, US Chairman of the Senate Committee on Armed Services, said Kiev used cluster bombs – claiming it’s because Ukrainian troops did not have better weapons delivered to them by the US.

READ MORE: US partly to blame for Ukraine’s use of cluster bombs – McCain

Reports from Donetsk coincided with the latest report from the German intelligence service, which estimates the real losses in the Ukrainian civil war at 50,000 dead (civilians and servicemen). This reported figure is nearly 10 times higher than the death toll named by the Kiev authorities.

READ MORE: 50,000 casualties in Ukraine? German intel calls Kiev’s 6k toll ‘not credible’

Meanwhile, the Ukrainian crisis became the center stage of discussions as the world leaders commenced for the Munich Security Conference.

READ MORE: Munich conference: Russia ‘hate fest’ or split between Western allies?

The latest breakthrough was announced on Sunday with plans for ‘Normandy Four’ format peace talks. The meeting may be held in the Belarusian capital, Minsk, as early as Wednesday, the German government said, following a phone call between Russia’s Vladimir Putin, Ukrainian President Petro Poroshenko, German Chancellor Angela Merkel and French leader Francois Hollande.

READ MORE: Ukraine crisis: Putin, Poroshenko, Hollande, Merkel voice plans for Minsk meeting