Spanish police officers working with the F.B.I. have halted an attempt by a major Mexican drug smuggling and distribution ring to establish a European operation, the authorities said Friday. The Interior Ministry announced that four people suspected of being members of the Sinaloa drug organization had been arrested in Madrid but offered few details. The ministry said the group wanted to make Spain a gateway for operations in Europe, even carrying out test runs using shipping containers without drugs. With information provided by an F.B.I. investigation that began in 2009, the Spanish police located the suspects and monitored them closely. In late July, investigators intercepted a container carrying 822 pounds of cocaine, and then moved in to make the arrests. One of the four suspects is said to be a cousin of the leader of the Sinaloa drug organization.