Spanish police said Thursday they had seized 1.8 tons of crystal meth that Mexico's Sinaloa Cartel was trying to sell in Europe, the country's "biggest-ever seizure" of the narcotic.

Police arrested five people during the raid in the eastern Alicante province, one of them a Mexican running the cartel's Spanish operation, a statement said.

"This is the biggest-ever seizure of crystal meth in Spain and the second largest in Europe," Antonio Martinez Duarte, head of the police's drug trafficking and organized crime unit, told reporters.

"Among those arrested is a Mexican citizen linked to the Sinaloa Cartel," he added.

He did not give his name but indicated the suspect was responsible for receiving the narcotics in Spain then distributing them within Europe.

According to Martínez, the group used houses in isolated areas in the Valencia region to store the smuggled shipments of methamphetamines before using vehicles with false bottoms to send them on to other European countries.

Police released video on social media showing officers removing bags of the apparent drugs that were hidden inside machinery and fake vehicle bottoms.

The Sinaloa Cartel is one of Mexico's oldest, largest and most violent criminal groups whose influence remains strong despite the arrest of its founder Joaquin "El Chapo" Guzman and his son.

Both have been extradited to and jailed in the United States. Last month, "El Chapo" had his request for phone calls and visits with his young daughters denied by a federal judge.

During the operation, police also detained three Spaniards and a Romanian, seizing five cars, documents, a weapon and cash.

But police believe it was a one-off trafficking operation and that "Mexican organizations are not permanently based" in Spain, Martinez Duarte said.

"These organizations send a trusted person who carries out the operation in line with their interests" and once that is over, he goes back home, he explained.

The seized narcotics had been due to be shipped to central Europe.

Although Spain is one of the main drug gateways to Europe, seizures of synthetic narcotics are uncommon as most traffickers usually deal in cannabis and cocaine.

In December, Spanish authorities confiscated 11 tons of cocaine hidden inside shipping containers and arrested 20 people. Nine months before that, police in northwestern Spain refloated a homemade semi-submersible vessel — a so-called "narco sub" they suspected was used to transport cocaine.

The Associated Press contributed to this report.

In:
• Drug Cartels
• Spain
• Cartel
• Methamphetamine