(CNN) Five South American countries and Canada want Venezuela placed under investigation as a humanitarian crisis continues to roil the country.
The leaders of Argentina, Chile, Colombia, Paraguay, Peru and Canada on Wednesday signed a joint statement addressed to the president of the International Criminal Court asking for a probe into possible crimes against humanity in Venezuela.
The alleged crimes, dating to 2014, include extrajudicial murder, torture and the arbitrary detention of political opponents and anti-government protesters.
The request, made at UN headquarters in New York as the UN General Assembly meets this week, is the first time ICC member governments have sought an investigation of alleged crimes that took place entirely on the territory of another country, Human Rights Watch said.
This multilateral move is the latest blow to Venezuelan President Nicolas Maduro, after the United States this week slapped sanctions on his wife and three other members of his inner circle in an effort to get Maduro to weaken his grip on the military and the government.
Once the richest country in Latin America, Venezuela has plummeted into an economic and humanitarian crisis, with food shortages, overcrowded hospitals, inflation and political turmoil. The chaos and ongoing crisis have triggered a mass exodus of Venezuelans seeking refuge in neighboring countries, ratcheting up tensions in the region.
The UN Office for the Coordination of Humanitarian Affairs calls the refugee crisis "one of the largest population movements in Latin American history." A related UN group, the International Organization of Migration, says the exodus of migrants from Venezuela is reaching a "crisis moment" on par with the Mediterranean flow of refugees from North Africa and the Middle East.
Why you should care about the Venezuela crisis
The agency estimates that from 2015 to 2017, the number of Venezuelans living outside the country more than doubled, from 700,000 to more than 1.6 million. About 31 million people live in Venezuela.
Maduro, speaking Wednesday at the UN General Assembly, called the humanitarian crisis in his country a "fabrication" and accused the United States and its Latin American allies of "trying to put their hands in our country."
The presidents of Argentina and Peru both denounced Maduro during their speeches at the UN conference.
The ICC, a tribunal based in the Netherlands, is already assessing whether to open an investigation on Venezuela, looking into allegations of excessive force and other abuses by the government in response to sometimes deadly anti-regime protests.
In a statement Thursday, ICC prosecutor Fatou Bensouda said the states' referral would not automatically result in such an investigation being launched.
However, she said that if she determined an investigation was warranted, the referral would expedite the process, because no judicial review of her decision would be needed.
Bensouda said it was the first referral submitted to her office by a group of states concerning a situation on the territory of another state.