20 Moroccans arrested under suspicion of stealing hundreds of electricity-generating solar panels worth 1.5 million EUR(US$2.14 million) and sending them for sale in North Africa.
The suspects are accused of stealing about 2,000 solar panels and shipping them to Morocco aboard ferries.
An investigation began in April when 238 panels were stolen from two solar power parks in the northern province of Palencia, a police statement said. Many Spanish cities, especialy in the country's south, boost electricity generation through the use of solar parks.
Police said the suspects were believed to have used violence during some of their heists.
Several more gang members were thought to be on the run, and international warrants have been issued for their arrest, the statement said.
The statement did not make clear when the arrests took place.