Ecuador deported hundreds of Colombian prisoners to their home country on Saturday as part of a measure aimed at easing overcrowding in the country’s prisons.

However, the decision was criticized by Bogota for being carried out unilaterally.

The detainees were transferred from various prisons to the Rumichaca international border bridge.

In February, Ecuadorian President Daniel Noboa said he would repatriate around 1,500 foreign inmates—out of the roughly 3,300 in Ecuador's prison system—as part of an effort to relieve overcrowding and reduce violence in the facilities.

Ecuador’s prison authority said in a statement Saturday that it had begun deporting 700 out of a total of 1,000 Colombian prisoners it plans to hand over to the neighboring country.

According to a report released Saturday afternoon, Colombia’s foreign ministry said that 603 of its nationals—543 men and 60 women—were expelled from Ecuador and were provided with assistance and food.

Background checks revealed that 11 of them had outstanding arrest warrants, including one with an Interpol notice, the statement added.

Colombia said it will insist on establishing a formal deportation protocol with Ecuador, especially since an additional 493 individuals are expected to be transferred in the coming days.

Colombia’s Foreign Minister, Rosa Villavicencio, who was at the Unified Command Post near the border, requested further information from Ecuadorian authorities, noting that only a list of 300 individuals had been provided so far, according to the ministry.

In June, Ecuador’s National Assembly approved a law allowing the expulsion of foreign prisoners to their home countries, banning them from reentering for 40 years under penalty of being declared military targets.

Ecuador’s prisons hold 35,000 inmates, although their official capacity is only 27,000.