Libyan, Egyptian and Chadian leaders were to meet Tuesday to discuss the situation in Sudan's troubled Darfur region a day after Sudanese President Omar al-Bashir's surprise visit to Cairo. Libyan leader, Moammar Gadhafi, who maintains close relations with some Sudanese tribes and rebel groups, has been involved in the efforts to solve the Darfur problem. The talks in Libya come after al-Bashir met with Egyptian President Hosni Mubarak on Monday to discuss an agreement the Sudanese leader signed with Chad's president last week in Saudi Arabia. The two neighboring countries, which share a 600-mile border, pledged to work together to quell the violence spilling over from Darfur and prevent opposition groups from staging cross-border attacks. Late last month, Libya hosted a conference aimed at exploring ways to persuade the groups fighting in Darfur to sign a comprehensive peace agreement after the Sudanese government and one major rebel group signed the Darfur Peace Agreement last year. But despite the 2006 agreement, violence has increased in Darfur. Ethnic African rebels have been battling the Arab-led Sudanese army and the pro-government janjaweed militiamen in Darfur for the past four years, killing some 200,000 people and turning the region of western Sudan into the world's largest humanitarian disaster.