Gunmen shot dead three tourists from Saudi Arabia in an attack in Niger's remote western desert, officials said Monday.

Three other Saudi citizens were also wounded in the assault, Niger government spokesman Mamane Kassoum Moktar told The Associated Press. Security forces have been sent to track down the unidentified attackers, he said.

Saudi Deputy Foreign Minister Khaled bin Saud told Saudi-owned Al-Arabiya TV the tourists were leaving Niger for neighboring Mali when they were attacked around dawn after stopping their vehicle to perform morning prayers.

It was not clear what sparked the violence, but local insurgents, bandits and members of Al Qaeda's Algeria-based North Africa branch are believed to be active in the remote deserts near the Mali frontier.

Asked if they suspected Al Qaeda was behind the attack, Saud said the group is active in the area "but we have no proof" they were involved.

"It appears to us so far that it was a robbery," Saud said, adding that authorities in Niger were in contact with their Saudi counterparts.