MEXICO, October 23 (RIA Novosti) - A mini-sub with 10 metric tons of cocaine onboard has been seized some 180 miles of the coast of Guatemala in the country's largest ever drug seizure, Mexican media reported on Friday.

Guatemalan Interior Minister Raul Velasquez said the drug was seized on Wednesday in a joint operation by U.S. anti-drug officers and Guatemalan military.

"A submarine without identification signs was detected on Wednesday by a Pacific naval base. U.S. frigates and Guatemalan air force planes took part in the sub's seizure," the minister said.

Three Colombian nationals and one Mexican citizen onboard the sub were detained. The submarine is currently being towed to the Guatemalan port of Quetzal.

According to preliminary reports, the cocaine was shipped to one of Mexico's drug cartels.

A total of 5.7 metric tons of drugs have been seized in Guatemala in 2009. The country's previous record drug seizure of eight metric tons was made in 2003.