A massive weapons cache of over 10,000 rifles, machine guns, pistols, revolvers, shells and grenades intended for sale to terror groups has been seized in Spain, Spanish authorities announced Tuesday.

In a disruption of a massive European terror weapons ring, five suspected weapons dealers were also arrested and $90,000 in cash was recovered during raids in Girona, Biscay, and Cantabria.

The seizure was the long-awaited fruit of an investigation launched by the Spanish police after a 2014 terror shooting at a Jewish museum in Brussels left four dead.

Aimed at reducing the number of illegal weapons circulating Europe, the effort led to the discovery of a trafficking gang whose complex operation “exploited legal loopholes and legislative differences between EU countries to divert guns from legal suppliers,” said Spain’s national police.

The gang had a workshop where they re-branded and reactivated the weapons to prepare them for black-market sales to terror cells in Spain, France and Belgium.

The seizure likely prevented dozens of potential terror attacks by snatching weapons destined to enable terror killings from the hands of criminals who would not have hesitated to use them against innocents.