BARCELONA, Spain (AP) — Spain's paramilitary national police force says its agents have confiscated more than 1.3 million posters, flyers and pamphlets promoting the planned independence referendum by Catalonia's regional government.

The Civil Guard said the campaign literature was seized on Sunday during raids of an unnamed business in Barcelona province that distributes advertising material.

The police force says the trove takes the number of items endorsing the independence referendum that have been confiscated to 1.5 million.

The Spanish government has vowed to stop the planned Oct. 1 secession vote, saying it's illegal. But Catalonia's leaders have pushed ahead even though Spain's Constitutional Court suspended a regional law that paved the way for the referendum and has agreed to review the vote's constitutionality.

Polls show Catalonia's 7.5 million residents roughly split on independence.