(Writes through with new quotes, details) By Diadie Ba DAKAR, Dec 31 (Reuters) - Suspected separatists in Senegal's restive Casamance province killed a prominent local ruling party official and slit his throat, security force officials said on Sunday. Armed men attacked Oumar Lamine Badji, a leading member of President Abdoulaye Wade's ruling Democratic Party (PDS), late on Saturday at his family home in the village of Sindian, around 50 km (30 miles) from the provincial capital Ziguinchor. "They came to Badji's home. They set his house on fire and fired shots nearby, and then slit his throat," a security force official in Ziguinchor, who declined to be named, told Reuters. He said security forces suspected the assailants were separatist rebels who have waged a low-level, on-off guerrilla campaign in the southern province since 1982. Badji's killing happened the night before Senegal's overwhelming Muslim majority celebrated Eid al-Adha, known locally as Tabaski, when Muslim families kill sheep, generally by slitting their throats. Casamance, Senegal's only predominantly Christian province, has seen more than two decades of low-level insurgency by the rebel Movement of Democratic Forces of Casamance (MFDC), who seek independence. However, the conflict has transcended religious and ethnic divisions, with rebels hailing from both religions and various tribes. Residents of the southern province, which is separated from the rest of Senegal by the former British colony of Gambia, complain of being marginalised. RENEWED VIOLENCE Violence subsided in recent years as Wade's government has renewed peace efforts, but fighting has intensified since mid-2006 after some rebels rejected peace talks. Speaking to state broadcaster RTS, Wade said condemned the killing of Badji, the leader of the Ziguinchor regional council, as "cowardly and ignoble". "There are some people who are opposed to peace, who will commit any kind of act, and it is they who commit aggression," Wade said after finishing Muslim prayers in the capital Dakar. "We will investigate and the republic will apply the law in the strictest manner." Commandant Daouda Diop, national spokesman for the gendarmerie, or paramilitary police, said Badji had been watching television with his family when the assailants began shooting. Diop said Badji had died of gunshot wounds, and his neck had not been cut. But security force officials and local media including the national news agency Agence de Presse Senegalaise reported that the assailants had slit Badji's throat. Fighting intensified in mid-2006 when government forces from Senegal and neighbouring Guinea Bissau, along with moderate MFDC factions, battled an armed MFDC wing which rejects peace talks. Suspected MFDC rebels killed two government soldiers and wounded 14 more in an attack 10 days ago. Senegal, one of the few African countries never to have had a coup d'etat, is regarded by foreign donors as a bastion of democracy in an unstable region. Wade, 80, is to seek a second and final term in office in elections in February.