Spanish police, in cooperation with the FBI, have frustrated the "first serious attempt" by Mexico's Sinaloa drug cartel to establish a foothold in Europe, authorities said here Friday.

The cartel's move was blocked by the arrest in Madrid of four suspected Sinaloa operators, Spain's National Police said.

One of the four Mexicans detained in the Spanish capital was Jesus Gutierrez Guzman, a cousin of cartel boss Joaquin "El Chapo" (Shorty) Guzman.

The arrests came a week after a consignment of 373 kilos (822 pounds) of 80-percent pure cocaine was intercepted in the southern Spanish port of Algeciras.

The shipment originated in Brazil and the four men nabbed in Madrid were planning to distribute the drugs throughout Europe, investigators said.

The drug seizure and arrests were the fruit of nearly two years of cooperation between Spanish police and the FBI under the ambit of Operation Dark Waters, a U.S. federal probe targeting the Sinaloa cartel.

U.S. agents tipped off their Spanish counterparts that cartel operatives were headed to Madrid in March 2011, when the four men arrested this week - and several suspected accomplices - spent around a week in the capital, apparently laying the groundwork for the cocaine consignment intercepted last week.

El Chapo Guzman, who escaped from a maximum-security prison in January 2001 and remains at large, appears on Forbes magazine's list of global billionaires. EFE