MADRID, SPAIN (AFP) - Spanish police said Thursday 74 people had been arrested in connection with an Internet pornography crackdown that turned up hard-core images of sexual attacks on young children.

Millions of child sex images were seized in the swoop including "extremely hard-core videos featuring such things as sexual attacks on very young children," police said in a statement.

Video footage will be analysed in an effort to identify the attackers and the victims and to determine whether any of the perpetrators are among those in custody, the statement added.

One of those detained was found with a camera containing pornographic images of a 13-year-old girl and another child.

Those arrested include engineers, computer specialists, students, government officials and one teacher, police said.

Using specialised tracking software, Spanish police can uncover the names and addresses of users logged on to illegal Internet sites.

In the past five years 1,200 people have been detained in connection with Internet child sex pornography.