Karim Khan
Karim Khan REUTERS/Michael Kooren

The International Criminal Court’s prosecutor, Karim Khan, officially opened an investigation on Wednesday into possible war crimes, crimes against humanity or genocide in Ukraine, The Associated Press reports.

The probe will cover crimes dating back to 2013, but will also cover the conflict sparked by Russia’s invasion of Ukraine.

Khan said in a statement he launched the probe after 39 of the court’s member states requested an investigation, a process known as a referral.

“These referrals enable my Office to proceed with opening an investigation into the Situation in Ukraine from 21 November 2013 onwards, thereby encompassing within its scope any past and present allegations of war crimes, crimes against humanity or genocide committed on any part of the territory of Ukraine by any person,” Khan said, adding, “Our work in the collection of evidence has now commenced.”

Khan had initially announced on Monday that he intended to open an investigation into possible war crimes committed in Ukraine, adding the investigation would be opened as "rapidly as possible".

Also on Monday, Human rights groups and Ukraine's ambassador to the United States accused Russia of attacking Ukrainians with cluster bombs and vacuum bombs.

Amnesty International and Human Rights Watch both said that Russian forces appeared to have used widely banned cluster munitions against Ukraine.

Oksana Markarova, Ukraine's ambassador to the United States, told reporters after meeting with members of the US Congress that Russia had used a thermobaric weapon, known as a vacuum bomb, in its invasion of her country.

"They used the vacuum bomb today," Markarova said after a meeting with lawmakers. "...The devastation that Russia is trying to inflict on Ukraine is large."