A group of lawyers on Thursday filed suit against Costa Rica, claiming it has violated the rights of dozens of minors deported from the United States by detaining them for nearly two months and by holding them in conditions “that could cause irreparable harm.”

This is the second high-profile legal challenge against a Central American nation that has agreed to take in hundreds of deportees expelled by the U.S. authorities — the result of the Trump administration’s effort to get other countries to help with mass deportations.

The latest lawsuit was filed by migrant rights lawyers before the U.N. committee that monitors the implementation of the Convention on the Rights of the Child.

Ian Kysel, a professor at Cornell Law School and a founding member of the Global Strategic Litigation Council, one of the organizations filing the lawsuit, said that because Costa Rica had agreed to additional measures under the U.N. treaty, complaints against it could be brought to the panel of experts.

That panel can issue a directive, he said, but, “ultimately, it’s going to be up to Costa Rica to follow it, and for other states who have signed on to this, to kind of shame them if they don’t.”

In February, 200 migrants from nations outside the Western Hemisphere, such as China, Iran, Vietnam and Uzbekistan, arrived in Costa Rica on two deportation flights from the United States. The group, which included 81 children, was then bused to a remote center hours from the capital, near the border with Panama, to wait there until migrants either asked to be sent back to their home countries or were granted asylum by some other nation.