Niger security forces have arrested three people suspected of a botched desert hostage-taking that left four Saudi Arabian citizens dead, military sources said.

The suspects, captured by soldiers near the Mali border shortly after the dawn attack on the group of travellers on Monday, have been transferred to the capital Niamey for questioning, the sources said on condition of anonymity.

One source said the suspects appeared to be foreigners.

"I can say that the suspects were not Nigerien," he said.

The attack, near the village of Djambala, comes in a restive zone where Tuareg rebels and al Qaeda cells are active.

Three Saudis were shot dead and three others in the group -- made up of six Saudis and two Malians -- were seriously wounded and transferred to hospital in Niamey.

One of the wounded Saudis later died of his wounds.

Saudi Arabia sent a plane to Niger to repatriate its two wounded citizens and the bodies of the four dead.

Military sources said the attack appeared to have been a hostage-taking attempt that had gone wrong.

The attack has increased tensions in the Sahel region, already wracked by a wave of hostage-takings. Four westerners -- three Spaniards and one Frenchman -- are believed to be in Mali and held hostage by al Qaeda operatives. – Reuters