Mexican marines have seized a record 50 tonnes of methamphetamine from a drug lab in the state of Sinaloa, authorities have said.
The military said it detected the lab in the town of Alcoyonqui, near the state capital Culiacan, and raided it on Thursday.
Officials said the drugs were hidden underground in two areas along with barrels of the chemicals used to produce meth.
"A clandestine narco-lab and two underground store rooms were secured and dismantled, with approximately 50 tonnes of processed crystal meth in solid and liquid form," the marines said in a statement.
The drugs were incinerated on site due to the difficult access to the remote location, the ministry said.
Mexico is a major supplier of methamphetamine to the United States and it the top source of heroin, which is fuelling a surge in opioid addiction.
The country is also the principal highway for cocaine trafficked north from South America.
Sinaloa is home to the drug cartel of the same name, formerly run by drug lord Joaquin "El Chapo" Guzman until his extradition to the United States in January 2017.
Local media reports said the lab was on territory controlled by the Sinaloa cartel.
The Mexican government deployed the army to fight the country's powerful drug cartels in 2006.
The strategy has led to numerous high-profile kingpin arrests and drug seizures. But it has also been accompanied by a wave of violence that has left more than 200,000 murders in its wake.