ADDIS ABABA (Reuters) - Ethiopia’s military has rescued six children kidnapped by South Sudanese raiders in a cross-border attack, an official said on Friday, but dozens of others remain missing and soldiers are pursuing the gunmen to recover them.

Officials said 28 people were killed and 43 children were kidnapped in attacks on Sunday and Monday in Ethiopia’s Gambella region, which shares a porous frontier with South Sudan.

“Soldiers engaged the bandits and brought back the children on Thursday,” said Umod Othow, a spokesperson for the regional government.

“Operations are taking place. Both the kidnappers and the remaining children are still inside Ethiopia,” he added.

The raids were another demonstration of how South Sudan’s civil war threatens to destabilize the region.

The oil-rich nation has been mired in a civil war since President Salva Kiir, an ethnic Dinka, fired his deputy Riek Machar, a Nuer, in December 2013. The resulting conflict has split the country along largely ethnic lines and forced more than 3 million people to flee their homes.

More than one million of them have found refuge in neighboring Ethiopia, Uganda, Kenya and Sudan. Regional governments have expressed fears that violence in South Sudan could spill over its borders into their own nations.