The suspects were nabbed by security forces in a central district of the capital on Tuesday after authorities seized two laboratories used to produce synthetic drugs, 50 kg (110 pounds) of chemical precursors, more than two tons of marijuana and 20 kg of cocaine, as well as an unspecified amount of money, rocket launchers and grenades.

Lopez Obrador, speaking at his regular morning press conference, said the unexpected release of the criminal suspects would be investigated but cautioned against a rush to judgment.

"Here the important thing is to see what the arguments were that were used to release these people," said the leftist leader, who took office in December. "Let's not rush. If someone acted improperly, illegally, if there was corruption, we will condemn it," he said.