Spanish police have detained nine men during raids against suspected Islamist militants believed to be linked to last year's deadly bomb attacks in Belgium.
Eight Moroccans and a Spanish national were arrested in and around Barcelona, in the north-east, police said.
The raids were co-ordinated with Belgian and Moroccan police.
The suicide bomb attacks on the Brussels airport and metro killed 32 people in March 2016. They were claimed by so-called Islamic State (IS).
As well as the 32 victims of the bombings, three suicide bombers died.
Several other men, some identified on CCTV as having been accomplices of the attackers, were subsequently arrested.
The group has been linked to the November 2015 Paris attackers.
On Tuesday, Spanish police said the nine suspects - aged between 30 and 40 - were seized during raids on 12 properties.
"Four of those who were detained have links with people arrested for the attacks carried out at Brussels airport and metro," a spokesman for Catalonia's regional police told the AFP news agency.
It was not clear whether the four had been directly involved in the attacks, the spokesman added.
During the raids police seized guns and drugs, as well as computers and memory drives, which were being analysed.
The names of the nine men detained - most of whom have criminal records - have not been released.
Meanwhile, police in Morocco searched several properties belonging to family members of those being held. It was not immediately clear if any arrests were made.
The raids were part of an operation that followed an eight-month long investigation, police said.