MADRID (AP) — A senior official in Spain's Catalonia region says police have not found any guns or explosives in the house of a man who allegedly attacked police officers with a knife in Barcelona before being shot dead.

Catalan Interior Minister Miquel Buch said Tuesday that authorities are investigating whether the man had any links to terror groups.

Speaking on Catalan public radio, he said that "as things stand" terrorism cannot be ruled out as a motive for Monday's attack at the police station on the outskirts of Barcelona.

Spanish news agency Europa Press also reported Buch as saying the investigation could last weeks and that the motive may not emerge until it is concluded.

Police are analyzing evidence collected during the house search.

Officials have not identified the dead suspect.