Sudan's National Intelligence and Security Services (NISS) have reported that Ibrahim Jibril's Justice and Equality Movement (JEM) faction, Darfur's strongest rebel group, has carried out a "terrorist operation" in the Bana region of western Chad. The attack allegedly targeted former JEM leaders who seceded from the rebel group to sign the Doha Document for Peace in Darfur (DDPD) last April. The DDPD stipulates reconciliation measures that would bring an end to the decade-long conflict between the Sudanese government and rebel groups in Darfur. The Qatar-brokered peace deal was signed by the Sudanese government and the Liberation and Justice Movement (LJM), an umbrella of small rebel groups, in July 2012. A JEM faction led by Mohamed Bashar joined the DDPD in April 2013. However, Jibril's faction continues to detract from the treaty. In a statement issued on Sunday night, the NISS claimed that Arko Soliman Daheya, Mohamed Beshr and five other former JEM leaders had been killed in an operation involving 20 members of Jibril's faction. Multiple vehicles were hijacked, including a Chadian security chief's car. Beshr, a former JEM military commander in chief, resigned in 2011 following former JEM leader Khalil Ibrahim's assassination. Daheya was the Sudan Liberation Movement (SLM) chief of staff before he joined the JEM in 2010 as deputy commander in chief. The NISS statement accused the JEM of "exercising criminality in the name of struggle" and asserted that "this aggression will not stop the peace process and the return the stability in Darfur." In a telephone conversation with Arabstoday, SLM chief Dr Osman Ibrahim Moussa described the assassination as "a dangerous indicator." He added: "The JEM and other groups have said that they will target leaders who sign bilateral peace treaties with the Sudanese government, and this constitutes a direct and dangerous threat for the peace process." Hashem Osman, vice president of the Freewill faction of the SLM, asserted that JEM actions "cast negative shadows on the DDPD, if they do not signify the complete death of the treaty." He cautioned that the attack could spur infighting between members of the Zaghawa tribe, which counts Ibrahim, Beshr and Daheya among its members. JEM recently assassinated Saleh Mohamed Gerbo, another former deputy commander, in an ambush in the Fouraweya region of north Darfur. Nahar Osman, JEM presidential advisor and member of the DDPD negotiating team, claimed that Jibril's faction has carried out successive attacks in an attempt "to destroy peace in Darfur."