S. Sudan weekend road ambush leaves 21 dead: police

Police spokesman Dominant Kawcgwok said a group of mostly women and children -- fleeing violence further north -- were travelling in a lorry between the capital Juba and the southern city of Yei when it "fell into ambush".

"We lost something like 21 people," and another 20 were wounded, he said.

The UNMISS peacekeeping mission has intensified its patrols in and around the South Sudan capital Juba ©Albert Gonzalez Farran (AFP/File)

The government has blamed the attack on rebel forces supporting former vice president Riek Machar, who fled to Khartoum after fighting broke out in Juba in July, according to local media.

In another incident on Monday, three passenger buses travelling between Juba and the Ugandan capital Kampala were attacked by unknown gunmen, Kawcgwok said.

However Ugandan police spokesman Felix Kaweesa, who confirmed the incident, said some passengers had been abducted.

"The gunmen shot and burnt one of the buses, they looted the buses and abducted several people," Kaweesa told AFP Monday.

"We are yet to confirm if there are any deaths during the attack," he said.

The United Nations Mission in South Sudan (UNMISS) said in a statement it had received "deeply disturbing reports of horrific violence" against civilians in Yei, some 150 kilometres (93 miles) southwest of Juba, near the borders with Uganda and the Democratic Republic of Congo.

UNMISS "is extremely concerned by the continuing deterioration of the security situation in Yei, Central Equatoria, where the Mission continues to be denied access," read the statement.

The UN refugee agency said last month that some 100,000 people were trapped in Yei after government troops surrounded the area.

In a joint statement, the European Union, Norway, the United States and Britain, together with Ethiopia, Kenya, Sudan and Uganda last week said they were "deeply concerned" about fighting in Yei, Wau (northwest), Bentiu (north), and Nassir (northeast).

South Sudan, which gained independence in July 2011, descended into war just two and a half years later when President Salva Kiir in December 2013 accused his former deputy Machar of plotting a coup.

Numerous attempts to shore up a fragile truce have failed, and in a major setback to peace efforts, fierce clashes erupted in Juba on July 8 this year between Kiir's guards and troops loyal to Machar.

Since the fresh violence in July, more than 200,000 people have fled South Sudan, sending the number of refugees from the war-scarred nation past the one-million mark, according to the UNHCR.

In a further blow to peace hopes, Machar last month urged "a popular armed resistance" against his rival Salva Kiir's government.

A displaced woman carries goods as UNMISS peacekeepers patrol outside the premises of the UN Protection of Civilians site in Juba on October 4, 2016 ©Albert Gonzalez Farran (AFP/File)

South Sudan, which gained independence in July 2011, descended into war just two and a half years later when President Salva Kiir in December 2013 accused his former deputy Machar of plotting a coup ©Albert Gonzalez Farran (AFP/File)