Three Mauritanians said to have links to an Algerian terrorist organization called al-Qaida of the Magreb are believed to have fled from Mauritania to neighboring Senegal. They are alleged to have killed four French tourists and severely wounded a fifth in eastern Mauritania. Police say the investigation is ongoing and they have already arrested several people they suspect of helping the suspects. Naomi Schwarz has more from VOA's West and Central Africa bureau in Dakar.

Senegalese authorities say they are on alert and looking for three men suspected to have fled there from Mauritania.

Senegalese National Police spokesman Daouda Diop says police have deployed all the necessary men and materials to conduct a thorough search.

Diop says if they are in Senegal, they will do everything to find them and send them back to the Mauritanian authorities.

The three men are suspected of killing four French tourists and wounding a fifth on Monday afternoon. The tourists, a father, his two adult sons, his brother, and his friend, were traveling in sports utility vehicles across southeastern Mauritania en route to Mali and Burkina Faso.

Authorities say the men stopped along the road near a town called Aleg for a picnic. Three men with guns pulled up in a black Mercedes, demanded money, and then shot all five. Only the father, a man in his seventies, survived, with severe bullet wounds to his legs.

Mauritanian journalist Salem Bokari says the police soon arrested two men and a woman, with criminal records for banditry. But he says they were later released, when the police turned their attention to a different set of suspects, with ties to an Algerian terrorist organization.

"A Mauritanian investigation, they are convinced that the attack is terrorist, made by very dangerous elements belonging to the terrorist al-Qaida in the North of Africa," said Bokari.

Bokari says the terrorist group, which used to be called the Salafist Group for Preaching and Combat, has not claimed responsibility for the act.

The Algerian Islamic extremist group has fought against the Algerian government and western interests in the region for more than a decade. They say they want an Islamist government in Algeria.

Bokari says the group does not have a large presence in Mauritania.

"It is not a popular group in Mauritania," he said. "Mauritanian Intelligence service thinks that there are about 20 persons who were there with the Algerian terrorist group linked to al-Qaida."

Bokari says the 20 Mauritanians are suspected to have received military training from the Algerian group before returning to Mauritania two years ago.

Islamic extremism has been on the rise throughout northern Africa from its base in Algeria. In September, al-Qaida's second in command called on northern Africans to "cleanse" their region of westerners. But Mauritania, a relatively stable and peaceful country, has not previously seen attacks against foreigners.

In just two weeks, mainly European racers in the annual Paris-Dakar rally will drive through Mauritania on their way to Senegal.