The Malian military accused Tuareg rebels on Tuesday over an armed attack previously blamed on Islamist fighters which left four civilians dead in the west African nation's war-torn north.
An army statement said a van carrying five people to the town of Tonka in the Timbuktu region on Thursday last week was attacked by gunmen who killed four of the passengers.
Several sources interviewed by AFP, including Tonka mayor Mamady Konipo, had blamed the deadly attack on suspected Islamists.
But a survivor had indicated the fighters were from the National Movement for the Liberation of Azawad (MNLA), a separatist group whose January 2012 offensive against the government touched off the cycle of unrest in Mali but now battles the Islamists alongside French troops.
Al-Qaeda-linked rebels ousted the MNLA and seized control of the fabled desert settlement of Timbuktu, along with the rest of northern Mali, in April last year before a French-led military campaign reclaimed the city in January.
Since then, the area has enjoyed relative calm while fierce fighting continues in the area around Gao, northern Mali's largest city, and the northeastern Ifoghas mountains, where armed Islamists are entrenched.