Ukraine President Volodymyr Zelensky has accused Russia of committing war crimes by targeting civilians in its bombing of the city of Kharkiv.
Mr Zelensky’s claim on Tuesday night comes after Oksana Markarova, the country’s ambassador to the United States, told reporters in Washington that Russia had also used a banned thermobaric weapon, known as a vacuum bomb, in its invasion of her country.
Rights groups have added their voice to the allegations that war crimes may have occurred during Russia’s invasion, and the International Criminal Court has indicated it is looking to launch an investigation.
Mr Zelensky said there were eyewitness accounts of civilians being deliberately targeted during Monday’s attack on Kharkiv, Ukraine’s second largest city.
There is “reasonable basis” to believe war crimes or crimes against humanity have been committed in Ukraine, ICC chief prosecutor Karim Khan said late Monday.
Amnesty International and Human Rights Watch both said that Russian forces appeared to have used widely banned cluster munitions, with Amnesty accusing them of attacking a preschool in north-eastern Ukraine while civilians took shelter inside.
Ms Markarova told reporters after meeting members of the US Congress that Russia had used a vacuum bomb.
“The devastation that Russia is trying to inflict on Ukraine is large,” she said.
A vacuum bomb, or thermobaric weapon, sucks in oxygen from the surrounding air to generate a high-temperature explosion, typically producing a blast wave of a significantly longer duration than that of a conventional explosive and is capable of vaporising human bodies.
There has been no official confirmation that thermobaric weapons have been used in the conflict in Ukraine.
CNN reported that one of its teams had spotted a Russian thermobaric multiple rocket launcher near the Ukrainian border early on Saturday afternoon.
White House press secretary Jen Psaki said she had seen reports but did not have confirmation that Russia had used such weapons.
“If that were true, it would potentially be a war crime,” she told a press briefing.
Ms Markarova said Ukraine was working actively with the Biden administration and Congress to obtain more weapons and tougher sanctions.
“They should pay. They should pay a heavy price,” she told reporters after leaving the meeting.
Amnesty International said international humanitarian law prohibits the use of inherently indiscriminate weapons such as cluster munitions.
Launching indiscriminate attacks that kill or injure civilians constitutes a war crime.