South Sudanese Gunmen Kill At Least 140 Civilians In Ethiopia, Government Says

South Sudanese gunmen killed more than 140 civilians and abducted at least 39 children in a raid in the Gambella region of Ethiopia Friday, the Ethiopian government said.

Ethiopia's communications minister Getachew Reda said the attackers were members of South Sudan's Murle tribe, but had no relation with either the government of South Sudan or South Sudanese rebels. The attack took place in a region that sits on the border of the two countries.

"The Ethiopian defense force is currently chasing after the perpetrators," Reda said, according to the Associated Press. He said Ethiopian security forces may cross into South Sudan to pursue the attackers. "They haven't crossed the border [yet], but they will if that's what it takes," Reda told Al Jazeera on Saturday. Reuters reports he said troops had already crossed the border.

The communications minister said Ethiopian forces had killed at least 60 of the attackers.

He told the AP that several children were abducted and taken back to South Sudan; the BBC reported the number of children was at least 39. The BBC adds that members of the Murle tribe "have previously been accused of carrying out cattle raids and stealing children to raise as their own."

About 272,000 South Sudanese refugees have been living in the Gambella region of Ethiopia since a civil war broke out in South Sudan in December 2013, after South Sudanese President Salva Kiir fired vice president Riek Machar. The resulting war has killed tens of thousands of South Sudanese and displaced more than 2 million. International powers pressured the two sides into a peace agreement last year, though some fighting has continued. According to Reuters, Machar says he will return to the capital Juba Monday and create a transitional government with Kiir.

Reuters reports that many people of the Nuer ethnic group — of which Machar is a member — live in Ethiopia's Gambella region. President Kiir is a member of the Dinka ethnic group. Human Rights Watch reported that violence in certain areas "has taken on an ethnic dimension."