Authorities in the kingdom have arrested five people after raiding computer shops selling compact disks containing hidden bomb-making instructions, a local newspaper reported on Thursday.

Police were questioning four owners of computer shops in the southern Jazan region and a fifth person believed to have supplied the CDs to the shops, Al-Watan newspaper said.

Officials were not immediately available for comment.

The daily said some of the shop owners might not have known about the bomb-making tutorial files hidden on the CDs. Only someone with technical knowledge would be able to find the files.

Saudi Arabia, the birthplace of al-Qaida leader Usama bin Ladin, has launched a crackdown on Muslim militants, especially after bombings in the capital Riyadh in May and November killed more than 50 people. The string of attacks have been blamed on al-Qaida.