MADRID -- Spanish police say they have arrested 79 people suspected of producing and distributing child pornography on the Internet.

Police say Saturday they arrested 78 men and one woman during the operation, which started in 2016.

In raids of 80 different properties across Spain, police agents confiscated 45 laptops, 113 hard discs, 25 mobile phones, and more than 300 DVDs that contained "extremely graphic" pornographic material involving minors.

Agents also found one hand gun, some smoke bombs, knives and drugs while raiding a property in Madrid.

Police say that the operation is one of the largest ever in Spain against child pornography.

It is not immediately clear how many people were charged or in custody.