DAKAR, Jan 14 (Reuters) - A veteran Senegalese separatist leader, Father Augustin Diamacoune Senghor, died overnight in a Paris hospital aged 78, an official of his rebel movement said on Sunday. Senghor, a Roman Catholic priest, was twice jailed as leader of the Movement of Democratic Forces of Casamance (MFDC), a restive southern region of Senegal, but signed a peace deal with the central government in 2004. Senghor had been transferred to a military hospital in Paris several months ago after his health deteriorated. "He died last night at the Val de Grace hospital," Ansoumana Badji, a senior MFDC official and former secretary-general of the movement, told Reuters in Senegal's capital Dakar. The MFDC has fought a low-intensity, stop-start guerrilla uprising since 1982 in the southern province, which is all but cut off from the rest of Senegal by Gambia. Senghor was jailed in 1982 and again in 1990 for his role in the rebellion. Fighting peaked in the 1990s and subsided in recent years due in part to peace efforts since President Abdoulaye Wade was elected in 2000. The 2004 peace deal which Senghor signed aimed to end the conflict, and envisaged a greater autonomy for Casamance, but disagreement over the deal split the MFDC and Senghor's leadership became little more than symbolic. Violence has flared again since mid-2006 as an armed wing led by hardline rebel commander Salif Sadio, who rejects peace, has fought against rival MFDC factions as well as the armies of Senegal and neighbouring Guinea-Bissau. Fighting in the north of Casamance in the last few months has prompted several thousand villagers to seek refuge across the border in Gambia.