Spanish authorities said Monday they had seized seven tons of cocaine hidden in shipping containers buried under a farm, arresting three suspected smugglers. Police released a video of the seizure, which shows officers digging in the ground and pulling out dozens of packages containing alleged drugs.

Civil Guard police said they launched the operation on Friday when they discovered two suspicious speedboats at the mouth of the Guadalquivir River.

The boats were followed to a rural property in the municipality of Coria del Rio, south of the city of Seville, where the suspects stored the drugs in two tanks hidden underground.

The Civil Guard, which said it was the largest seizure of cocaine smuggled into southern Spain by speedboat, announced video on social networks showing officers digging up the alleged drugs.

They said they seized three weapons, including an AK-47 assault rifle, and two stolen vehicles.

Spain is one of the main gateways to Europe for international drug traffickers due to its proximity to Morocco, the largest producer of cannabis, and close ties to former colonies in Latin America.

Last month, Spanish authorities arrested one of their top police officers after €20m was found in the walls of his home, as part of an investigation the largest cocaine bust in the country.

In July, Spain participated in the destruction of a large network that transports Latin Americans cocaine to Europe by boat, which included 50 arrests in eight countries. Twenty-six of those arrested were arrested in Spain.