Senegal will triple the size of its troop contingent in Sudan's war-wracked Darfur region, increasing the number of its soldiers there to 1,600, the Foreign Ministry said Thursday. The West African nation has 538 troops in Darfur - part of a beleaguered 7,000-strong African Union peacekeeping force struggling to help end four years of rape and slaughter of civilians in the vast desert region. Last week, the UN Security Council unanimously approved a 26,000-strong force in Darfur. The new UN mission is expected to absorb the AU force and take over responsibility for peacekeeping by Dec. 31. If the force is fully deployed, it would be the world's largest peacekeeping operation.