Mexico has begun filing criminal complaints with state prosecutors in the United States over the deaths of its citizens in U.S. immigration custody and during enforcement operations, the foreign ministry said on Tuesday.

Mexico’s government has also sent cease-and-desist letters to U.S. detention centers where Mexican nationals have died, the ministry added in a statement.

The filings follow the deaths of at least 14 Mexican nationals in ICE custody and several others during arrest operations, including the recent fatal shooting of a Mexican citizen by an ICE agent in Houston.

President Claudia Sheinbaum announced Mexico’s intention to escalate its response to the deaths last Friday, as she claimed that the government “cannot turn a blind eye to the Mexicans who have died.”

In addition to the measures in the U.S., Mexico’s foreign minister also contacted the United Nations High Commissioner for Human Rights regarding the deaths of Mexican nationals in ICE custody.

Mexico expects the U.N. office to gather information from U.S. authorities, analyze the events and “refer the case to the relevant special procedures of the Human Rights Council,” the statement added.

(Reporting by Aida Pelaez Fernandez and Natalia Siniawski; Editing by Daina Beth Solomon)