Five Indian peacekeepers and at least seven UN civilian staff were killed on Tuesday in an ambush in South Sudan, officials said, a day after warnings about spiralling violence there.
"Five peacekeepers from India with UNMISS (United Nations Mission in South Sudan) killed in ambush in Jonglei," Indian foreign ministry spokesman Syed Akbaruddin wrote on Twitter, adding that four had been wounded.
He confirmed the deaths at the hands of unknown "rebels" to AFP and said the soldiers had been killed while "escorting a UN convoy".
Hilde Johnson, the top UN official in South Sudan, "condemns in the strongest terms the killing today of a number of peacekeepers and several civilian staff in an ambush by unidentified assailants," a UN statement said.
A UN source who asked not to be named told AFP that "seven or eight" civilians were killed, who are believed to include South Sudanese staff.
The eastern state of Jonglei has been the scene of widespread ethnic conflict since South Sudan became independent in July 2011, with bloody battles between rival tribes, including the Dinka, Lou Nuer and Murle people.
Much of the trouble has been in Pibor county, where the UN peacekeeping force is based.
Bloody clashes between the army and a former theology scholar turned rebel called David Yau Yau from the Murle people have devastated large parts of this troubled region.
An Indian soldier was shot and wounded there in March amid high tensions about an imminent government crackdown on rebels, while the army shot down a UN helicopter in December, killing all four Russians on board.
Amid renewed clashes between ethnic groups and government forces, UN troops have recently stepped up their patrols to deter violence and fulfil their mission of protecting civilians.
Johnson warned Monday about the "destabilisation" of the region.
"Without stability and peace in Jonglei, the largest state in South Sudan, in the long run stability also in the country could be at risk," she told reporters.
"I urge the Murle, Lou Nuer and Dinka communities, their leaders, and the governments of Jonglei and South Sudan to resume and sincerely engage in peace initiatives," she added.
South Sudan's army launched the latest offensive against Yau Yau's rebels in March.
India is a major contributor to UN peacekeeping forces around the world and has suffered losses in the past.
In 2010, rebels hacked to death three Indians in their camp in the Democratic Republic of Congo.
Akbaruddin said that the Indian foreign ministry was arranging for the bodies of its peacekeepers in South Sudan to be returned home.
At the end of 2011, barely six months after South Sudan declared independence after decades of civil war with the north, some 8,000 armed Lou Nuer youths rampaged through Pibor County, vowing to exterminate their cattle-keeping rivals, the Murle.
The UN estimated that over 600 people were killed and around 300 in smaller revenge attacks.
A subsequent state-wide disarmament campaign led by security forces and mired in claims from rights groups of abuses against civilians, pushed some residents towards Yau Yau's militia.