Police in Spain have neutralized a “very active and effective business network” that allegedly supplied a variety of materials to terrorist groups, the country’s interior ministry said Thursday.

A counterterrorism investigation last month led to the arrest of seven people who are accused of providing “logistical and financial support” to the Islamic State and the Syrian al-Qaeda affiliate Jabhat al-Nusra, the ministry announced in a news release. Authorities also confiscated about 20,000 uniforms and other accessories that could have been used “to equip an army that would be perfectly prepared for combat” out of three shipping containers in Valencia and Algeciras.

The ministry said the containers were tied to the business network, and had been labeled as carrying “second-hand clothes” so as not to arouse suspicion from customs officials. However, authorities discovered bundles of uniforms hidden among other clothing inside the containers.

The now-neutralized network helped provide a constant supply of weapons, military equipment and other technological supplies to areas controlled by the Islamic State, the ministry said.