Lawyers for Ukraine at the top U.N. court rejected Russia's account of the downing of a Malaysian airliner as a "rambling conspiracy theory", in a case alleging Moscow backed separatists in eastern Ukraine in 2014.

Kyiv says that Moscow violated a U.N. anti-terrorism treaty by equipping and funding pro-Russian forces, including militias who shot down Malaysian Airlines Flight MH17, killing all 298 passengers and crew in July 2014.

Last November, a Dutch court convicted two Russians and a Ukrainian separatist in absentia for their role in the downing of the airliner and sentenced them to life in prison. It found that Russia had "overall control" over the separatist forces.

Russia at the time rejected the decision by the Dutch court. Last week, in hearings before the International Court of Justice, also known as the World Court, Russia said Ukraine's MH17 case was based on "nonsense" and offered a host of alternative explanations for what happened.

On Monday, Ukraine's lawyers hit back. One of them, Marney Cheek, told the court it had been "subjected to a rambling conspiracy theory" about the shooting down of MH17 which would be "better relegated to the darkest corners of the internet".

Kyiv has accused Russia of being a terrorist state and said it had also tried to erase the culture of ethnic Tatars and Ukrainians in Crimea, which Russia annexed from Ukraine in 2014. Kyiv has asked the court to find Moscow guilty of breaching its treaty obligations and order it to pay reparations.

Russia denies systematic human rights abuses in Ukrainian territory that it occupies. It also says it has met its obligations under the U.N. treaty against financing terrorism. Russia will get a last chance to reply to Ukraine's allegations on Thursday.

The World Court case stems from 2017 and was filed well before Russia's full-scale invasion of Ukraine in February 2022. The International Court of Justice is expected to rule on the case before the end of this year.