South Sudan and Uganda will jointly investigate recent deadly clashes on their border, the South Sudanese army said on Sunday, after six people died in fighting.

Last month, clashes erupted between the Ugandan People's Defence Forces (UPDF) and South Sudanese troops in South Sudan's Central Equatoria state.

It was unclear what had triggered the clashes, with both sides giving differing accounts, which killed five South Sudanese security force members and one Ugandan soldier.

South Sudanese army spokesperson Lul Ruai Koang said the Ugandan army chief Muhoozi Kainerugaba had met his counterpart "on the need to immediately de-escalate the worsening security situation along the common border."

Fourteen-member committee

A 14-member committee with "equal representation from both armies" would be established to investigate the "exact causes" of the clashes in Central Equatoria, he said, in a statement posted on Facebook.

Uganda's army chief Kainerugaba arrived in South Sudan's capital Juba on Saturday and also met with President Salva Kiir, according to a UPDF statement.

The two spoke on "focusing on strengthening bilateral relations and regional stability", it said.

Uganda sent troops to support Kiir when civil war broke out in the country in 2013, just two years after it gained independence from Sudan.

Deadly civil war

The South Sudanese civil war lasted five years and left approximately 400,000 people dead before a power-sharing agreement was reached in 2018 between President Kiir and First Vice President Riek Machar.

Uganda again deployed special forces in March this year.