Police officials in northeastern Spain said Wednesday that they arrested at least nine people with suspected links to the Islamic State group and other terror activities, according to media reports. The arrests were conducted amid a growing threat in the region over an increasing number of people attempting to join militant groups in Iraq and Syria.

The arrests were made early Wednesday in five northeastern towns, including the regional capital of Catalonia, Barcelona. Nearly 360 officers from Mossos d'Esquadra regional police conducted 13 raids, making it the biggest operation against jihadist activities in the country, the Associated Press reported, citing an official statement. The operation was planned by Madrid’s National Court.

There are, however, conflicting reports about the number of arrests made. Ten people were arrested in the operation, according to the AP. 

"The arrested are accused, amongst other crimes, of belonging to a terrorist organization," a spokeswoman for the Catalan police said, according to Reuters, which reported that nine people were arrested.

The Catalan police said in a statement, according to the Spain Report (TSR), that those arrested “are allegedly involved in several crimes related to jihadi terrorism, especially linked to the orders of the terrorist organization Islamic State/DAESH.” The operation started at 4:00 a.m., local time (10:00 p.m. EDT Tuesday).

The report by TSR also cited Catalan Home Secretary Ramón Espadaler as saying on Wednesday that the arrests had risen to 11, including 10 men, one woman and a 17-year-old. Espadaler reportedly said that five of them were Moroccan, while five were non-immigrant non-nationalized Spaniards and one from Paraguay.

The group was allegedly hiring, radicalizing and sending people to fight with ISIS. “There is jihadism and a jihadi presence in Catalonia. That is a reality,” Espadaler said, according to TSR, adding: “Of the 11 people arrested, five are converts to Islam, the Spaniards and the Paraguayan.”

So far this year, Spanish officials have arrested nearly 30 people suspected of being involved in militant activity, including radicalizing young Muslims and helping them join jihadists in Iraq or Syria or targeting sites at home, Reuters reported.

Last week, the Catalan police detained four people from a single family, including 16-year-old twin boys, who were trying to reach Syria to fight alongside jihadi fighters.