KIEV: Ukraine’s armed forces on Tuesday rejected allegations that they indiscriminately used banned “cluster bombs” in the six-month war against pro-Russian insurgents in the separatist east.

Human Rights Watch on Monday published a detailed investigation carried out jointly with The New York Times that identified 12 incidents in which these weapons killed six people — including a Swiss aid worker — in and around the rebel-held city of Donetsk earlier this month.

The global rights group said there appeared to be “widespread” use of these weapons, which are highly inaccurate as they are sprayed across a wide area.

The report supported claims made throughout the conflict by Russia that Ukraine’s pro-Western government had been violating human rights and killing innocent civilians through indiscriminate use of force.

“It is shocking to see a weapon that most countries have banned used so extensively in eastern Ukraine,” said Human Rights Watch researchers Mark Hiznay.

The report said one of the cluster bomb attacks was responsible for killing a Swiss International Committee of the Red Cross worker in Donetsk on October 2.

Human Rights Watch urged Ukrainian forces to “immediately make a commitment not to use cluster munitions” and for the government to “accede to the treaty banning their use”.

The 2008 Convention on Cluster Munitions banning their use has been signed by 113 parties but not Ukraine or the United States.

Cluster munitions contain dozens or even hundreds of smaller explosives that are carried by bombs or rockets.

Human Rights Watch said these smaller explosives “are spread indiscriminately over a wide area, often the size of a football field, putting anyone in the area at the time of attack”.

Two top Ukrainian military officials denied using such weapons when contacted by AFP.

“These charges are groundless,” said Ukrainian defence ministry spokesman Bogdan Senyk.

Ukraine’s eastern campaign spokesman Vladyslav Seleznyov further dismissed what the rights group described as evidence showing that the military shelled civilian neighbourhoods in industrial cities of Donetsk — home to nearly a million people before the war.

“Human Rights Watch knows that these are banned weapons — and we do not use banned weapons,” Seleznyov said by telephone.

“Neither do we shell civilian neighbourhoods because this endangers lives. But our opponents constantly attack these neighbourhoods,” Seleznyov added.

AFP reporters across the eastern industrial war zone have witnessed repeated shelling attacks on city districts that have contributed to a total death toll that UN rights officials estimate at 3,700.

But it is usually impossible to say with any certainty whether these shells and rockets are fired by the insurgents or Ukrainian forces.

Most attacks are conducted from a distance of a few dozen kilometres and both sides accuse the other of responsibility.

Human Rights Watch said that “while not conclusive, circumstances indicate that anti-government forces might have been responsible for the use of cluster munitions.”

Separatist leaders issued no immediate comment.