South Sudanese leaders are trading accusations over who is responsible for a cross-border attack in Ethiopia which Ethiopia's government said resulted in deaths of 208 people and triggered an incursion by Ethiopian troops into South Sudan.

Ethiopia announced Wednesday its military entered South Sudan and surrounded the attackers, believed to Murle tribesmen who abducted 125 children.

Baba Medan, the governor of South Sudan's Boma state, where Murle and other groups live, said dissident members of the Cobra faction were responsible. The Cobra was a rebel militia comprising Murle and Anyuak tribes which signed a peace deal with South Sudan's government in 2013 and has been integrated into the national army.

David Yau Yau, who led the Cobra rebellion, denied any involvement of his former troops and accused the governor.