SAUDI authorities have beheaded a man convicted of attacking a woman and snapping nude photos of her in order to blackmail her for sex.

A Saudi Interior Ministry statement carried in national papers today said the man broke into the woman's apartment and attacked her husband before turning on the woman. It was not clear when the attack took place.

The statement said the assailant, who was not identified, was beheaded with a single sword stroke on Friday.

Saudi Arabia follows a strict interpretation of Islam under which people convicted of murder, drug trafficking, rape and armed robbery can be executed - usually with a sword.

According to an Associated Press count, Saudi Arabia has executed 31 people so far this year. The kingdom executed 27 people last year.