MADRID — The Spanish police on Friday carried out the first arrests in Western Europe of citizens accused of traveling to Ukraine to fight on the side of the Russian-backed rebels there.
Eight Spaniards were arrested in dawn raids across different regions of Spain, including in Madrid and Barcelona, the Interior Ministry said in a statement.
Those arrested, the ministry said, recently returned to Spain after going to Ukraine last year to join pro-Russian troops around Luhansk and Donetsk. The ministry said that they had been identified partly by information that the eight had posted online, including photographs of themselves wearing paramilitary uniforms and training with explosives and assault rifles.
The fighters are likely to be charged with participating in activities considered to be terrorism by Ukraine, the ministry said, including taking part in assassinations and carrying illegal weapons. The ministry also said that fighting in Ukraine could in itself amount to a violation of “the neutrality of Spain.”
A spokeswoman for the Spanish National Police said that it could not release further details because the police operation was continuing. The Spanish news media reported that those who were arrested included former members of the Spanish military.
Francisco de Borja Lasheras, associate director of the Madrid office of the European Council on Foreign Relations, a think tank, said there was “a long narrative among certain segments of the Spanish left that anything that happens in Eastern Europe is a C.I.A. conspiracy and part of a Western imperialist agenda.” That narrative, he suggested, blended with “a certain nostalgia for the Soviet Union” that could be traced back to the Spanish Civil War, when “the Soviet Union was the only power supporting directly the Spanish Communists.”
Until now, Spain’s efforts to stop its citizens from taking part in overseas conflicts have focused on fighting in the Middle East, particularly in Syria, where the government says dozens of Spaniards might have joined the ranks of Islamic State militants.
Last year, the Spanish police arrested 47 people accused of recruiting fighters for the Syrian conflict. The police said on Tuesday that they had arrested four people accused of setting up online platforms to persuade young women to join Islamic State fighters in Iraq and Syria. Two of the arrests were made in Melilla, a Spanish enclave in northern Africa that has turned into a hot spot for the recruitment of Islamic fighters.
Since the start of the war in Ukraine, several associations showing support for rebels in that country have formed in Spain and in other European countries.
Among the Spanish groups is the Brigada Internacional Carlos Palomino, which posted a message online last year denouncing American support to Ukraine and promising that the fighting in eastern Ukraine would be “the grave of fascism.” The brigade took its name from a teenager who was killed on the Madrid subway in 2007 by a soldier linked to neo-Nazi groups.