Spanish police have arrested a fourth terror suspect believed to be linked with a gang trying to buy explosives for an attack.
Spain launched a crackdown after the Madrid train attacks
The man was arrested in Barcelona, days after three Moroccans were detained in the same city.
He will be sent to Madrid, where the other three are also being questioned, suspected of links to "international Islamist terror networks", reports say.
The Spanish authorities have increased security for the Christmas season.
In March attacks by suspected Muslim militants killed 191 people in the capital, Madrid.
More than 120 people have been arrested in connection with the bombings.