Regional authorities in Catalonia on Thursday denied news reports that U.S. anti-terrorism officials had warned them of an attack targeting Barcelona, but acknowledged that they did receive tips of possible attacks from other sources that they deemed not credible enough.

Catalan regional interior chief Joaquim Forn said regional police were not warned by the CIA or the National Counterterrorism Center in the U.S. about the Aug. 17 van attack on Barcelona’s famous Las Ramblas boulevard that killed 14 people. Forn added that such warnings are typically made through state channels.

Barcelona-based El Periodico newspaper reported that the U.S. sent a warning on May 25 to regional police, specifically mentioning Las Ramblas. Other Spanish media outlets published similar stories.

Regional police senior officer Josep Lluis Trapero said there were generic warnings of an attack, including one received May 25, but he said both Spanish and Catalan authorities considered them not reliable though.

He said the warnings did not come from the CIA or the NCTC but he gave no details on their source.

Forn accused El Periodico of trying to discredit the regional police.

The Aug. 17 van attack killed 14 people, and one other person was stabbed to death by the Barcelona attacker as he fled. Another attack in nearby Cambrils a day later left one dead. The attacks were claimed by the Islamic State group.

The U.S. embassy in Madrid said it could not comment on intelligence issues.

(AP)