Story highlights

The warning comes after the militias kill 39 in a neighboring state

The government says the attackers were part of the South Sudan Liberation Army

The rebels say they are fighting corruption and domination

South Sudan became a nation in July, separating from Sudan

CNN  — 

A South Sudan rebel group warned the United Nations and residents to leave a remote border state within three days or risk coming under fire as it launches an attack on the local government.

The South Sudan Liberation Army said Saturday it was headed to Warrap state after an earlier attack on Mayom town in neighboring Unity state.

Both states are in South Sudan, near the border with Sudan.

The goal is to “liberate” the state from the government in Juba, the group said in a statement.

“Within few days, the people of Warrap will be liberated from abject poverty, corruption and abuse of human rights,” the militia said. “We would also advise the civilians to evacuate all towns and move to villages in order to be safe,” it said.

The warning follows an attack in oil-rich Unity state that killed 39 people, a South Sudan government spokesman said Saturday.

Yein Matthew, the government spokesman, said the attacks in Mayom were carried out against civilians by militias of the South Sudan Liberation Army.

South Sudanese government forces were pursuing the attackers through nearby woods, according to Matthew. One militia leader has been captured and is being questioned.

Liberation army members have clashed with the military of South Sudan, which separated from Sudan and became independent in July.

The South Sudan Liberation Army, for instance, has said that it is fighting corruption and domination of Dinkas, the new nation’s main ethnic group.

South Sudanese President Salva Kiir has offered amnesty deals to the rebels. Several truces have not been honored, according to the Enough Project, which seeks to end genocide and crimes against humanity.

CNN’s Brian Walker contributed to this report.