A man accused of killing four French tourists escaped from a courthouse after an interrogation session Wednesday, tricking guards who believed he was inside a restroom, a courthouse official and a witness said.

Sidi Ould Sidna was arrested in January in connection with the killings of the tourists, who were gunned down on the side of a highway in Mauritania, a relatively stable democracy in West Africa.

The killing of the tourists and a subsequent attack on a Mauritanian military outpost led organizers of the Dakar Rally to cancel the race's trans-Saharan course, moving the race to Latin America, a major blow to the economy of the desert region.

Sidna, 26, had just finished a round of questioning Wednesday at the capital's courthouse when he asked his guards for permission to go to the bathroom. A witness said the guards allowed him to go into the stall by himself, but did not guard the doorway. When he re-emerged, Sidna ran for the courthouse's exit and quickly blended into the crowd outside.

Deputy prosecutor Moustapha Ould Said confirmed that Sidna had escaped, saying "the fugitive was able to divert the attention of the policeman that was guarding him."

The prosecutor declined to explain how this happened, but Abdallahi Fall, a witness who was in the courthouse at the time of the escape, said he saw the policeman that was guarding the bathroom leave to approach a group of his friends.

"It was when Ould Sidna came out of the bathroom that he realized the policeman was not in front of the door that he decided to flee," said Fall, who had come to the courthouse to attend to a legal matter.

Once on the street, Sidna merged with the crowd outside that had gathered on the main boulevard flanking the downtown courthouse to await the arrival Wednesday of the emir of Qatar.

Sidna was one of two men arrested in January in the West African country of Guinea-Bissau in connection with the killings. The suspects were extradited to Mauritania, where they are facing charges of murder and terrorism.

The tourists were gunned down on the side of a Mauritanian highway on Dec. 24, where they had stopped to have a picnic near the town of Aleg, 155 miles south of the capital, Nouakchott. Mauritanian officials say the men behind the attack are linked to an Al-Qaida-affiliated terror cell headquartered in neighboring Algeria.