South Sudan's First Vice-President Riek Machar has been charged with murder, treason, and crimes against humanity in a move that some fear could reignite the country's civil war.

Justice Minister Joseph Geng Akech said the charges against Machar relate to an attack in March by a militia allegedly linked to the vice-president. The roads leading to his house in the capital, Juba, have been blocked by tanks and soldiers.

Forces loyal to Machar fought a five-year civil war against those backing President Salva Kiir until a 2018 peace deal ended the fighting in the world's newest country.

Machar has been under house arrest since March, with the UN, African Union and neighbouring countries all calling for calm. The relationship between Machar and Kiir has become increasingly strained amid ethnic tensions and sporadic violence.

Seven others have been charged alongside Machar, including Petroleum Minister Puot Kang Chol and Army Deputy Chief of Staff Lt Gen Gabriel Duop Lam. Another 13 suspects remain at large.

The March attack was carried out by the White Army militia, largely made up of fighters from the Nuer ethnic group, like Machar, reportedly resulting in 250 military deaths, including a general, and the death of a UN helicopter pilot.

Justice Minister Akech emphasized that the case sends a clear message of accountability for those committing atrocities in the country, regardless of their political stature. Machar has not commented on the charges.

South Sudan gained independence in 2011, but civil war erupted two years later, leading to a significant loss of life and displacement.