– Four Cuban exiles from Miami have been detained on the island and accused of planning “terrorist actions,” Havana authorities said Wednesday, the first such arrests in years.

The Interior Ministry said the men were taken into custody on April 26 and alleged that their targets were military. Few details were released, and it was not clear why it took so long to make the arrests public.

“They intended to attack military installations with the goal of perpetrating violent actions,” the ministry said in a statement published by Communist Party newspaper Granma.

The arrests come amid increased exchanges between exiles and their homeland, including visits by several prominent former hard-liners who had vowed never to set foot on the island while brothers Fidel and Raul Castro were still in charge.

Cuba’s Interior Ministry was reaching out to U.S. authorities to investigate.