TALLINN, Estonia (AP) — More than 2,400 Ukrainian children aged 6-17 have been taken to Belarus from four regions of Ukraine that are partially occupied by Russian forces, a study by Yale University has found.

The study, released Thursday by the Humanitarian Research Lab of the Yale School of Public Health, which receives funding from the U.S. State Department, found that “Russia’s systematic effort to identify, collect, transport, and re-educate Ukraine’s children has been facilitated by Belarus,” and is “ultimately coordinated” between Russia’s President Vladimir Putin and Belarus’ authoritarian leader Alexander Lukashenko.

“Belarus’ direct involvement in Russia’s forced deportation of children represents a collaboration” between the two, “with various pro-Russia and pro-regime organizations facilitating the deportation of children from Ukraine,” the research said.

According to the study, at least 2,442 children, including those with disabilities, were taken to Belarus from 17 cities of the Donestk, Luhansk, Kherson and Zaporizhzhia regions of Ukraine between Feb. 24, 2022 and Oct. 30, 2023. The effort has been described in great detail in the 40-page report.

From the occupied Ukrainian regions, the children were taken to the Russian southern city of Rostov-on-Don, and then put on a train to Belarus. The transportation was funded by the Belarusian state, and state organizations were involved per Lukashenko’s approval.

A total of 2,050 of them were taken to the Dubrava children’s center in the Minsk region of Belarus, while the other 392 were brought to 13 other facilities across the country. There, the children were subjected to re-education and military training, including with Belarus’ law enforcement and security services, the report said.

It also named several key players involved in the effort, including Belarusian public figure Alyaksei Talai, Belarus’ state-owned potash producer Belaruskali, the Belarusian Republican Youth Union, and pro-Russia ultranationalist motorcycle clubs.

Ukrainian authorities have said that they’re investigating the deportations as possible genocide. Ukraine’s Prosecutor General said Belarus’ role in forced deportations of more than 19,000 children from the occupied territories is also being investigated.

Earlier this year, the International Criminal Court indicted Putin and his children’s rights commissioner Maria Lvova-Belova for their alleged involvement in crimes connected to the deportation of children from Ukraine and issued arrest warrants for them. Belarusian opposition has been seeking a similar indictment for Lukashenko.

Pavel Latushka, a former Belarusian minister turned opposition leader in exile, said he has handed evidence to the ICC implicating Belarus’ president.

Latushka told The Associated Press on Friday that the Yale report complements the data he and his team have gathered with additional “horrible details” and “raises the question of international criminal prosecution of the main Belarusian criminals that organized unlawful transfer of Ukrainian children to Belarus.”

“Democracy wins when there is accountability, and Lukashenko and his associates commit thousands of crimes against Belarusians and Ukrainians,” Latushka said.

The U.S. State Department in a statement announcing the Yale report on Thursday said Washington “will continue to pursue accountability for actors involved in abuses connected with Russia’s war against Ukraine.”