The Mexican government's human rights agency is urging the army not to use ambiguous terms in orders, after activists revealed the army had essentially issued a directive to troops to kill suspected criminals.

The National Human Rights Commission said Tuesday it made a formal request to the Defense Department asking that it review and correct the language it uses to avoid "imprecise or ambiguous" language.

Last week, activists for the Miguel Agustin Pro Juarez human rights center released a copy of military orders issued to an army squad that killed 22 suspects in June 2014. Investigations found 12 to 15 of the suspects were shot to death after surrendering or while unarmed.

The soldiers' orders directed them to "abatir" criminals, a word almost universally understood in Mexico as meaning "kill."