A MAURITANIAN who was arrested in Senegal after US officials suspected him of plotting a foiled terrorist attack in the United States in December has been expelled to Mauritania. Mohambedou Ould Slahi was arrested last Saturday at Dakar airport, after US police said he was involved in the attack foiled in December when Algerian Ahmed Ressam was stopped in Seattle, Washington, with explosives in his car. Senegal expelled Slahi on Wednesday, the source said.