MEXICO CITY - Mexico has nearly emptied the 65 migrant detention centres it has across the country by returning 3,653 people to Guatemala, El Salvador and Honduras, the National Migration Institute said Sunday, adding the move should help avoid COVID-19 outbreaks in the once-crowded facilities.

The institute said in a statement that only 106 migrants remain in the centres, which have a capacity for 8,524 migrants.

While in March they were filled to less than half their capacity, before that there were complaints of overcrowding and poor hygiene conditions, especially last spring. Various migrant rights and international groups had urged Mexico to release the mainly Central American migrants to avoid an outbreak of the new coronavirus.

Mexico began to empty the centres on March 21 in line with policies issued by United Nations agencies, but border closures by the governments of Guatemala, Honduras and El Salvador delayed returns, the institute said.

In the return process, Mexico’s government prioritized minors, the elderly, families, pregnant women and migrants with risks of chronic diseases. Mexico’s justice system this month issued a resolution demanding the release of all migrants in vulnerable situations.

Mexico’s migration agency said it does not handle the transfer of Mexican nationals returned by the United States but made no reference to Central Americans returned by U.S. authorities to Mexico.