"Unfortunately, just this very morning such militia groups have targeted and killed three soldiers from India in South Sudan," India's Ambassador to the UN Asoke Mukerji told a UN meeting on peacekeeping last evening.
Rebels from the second-largest ethnic group, the Nuer, stormed the base in Akobo in Jonglei state, targeting civilians of the majority Dinka ethnic community.
3 Indian peacekeepers were killed when attackers stormed a UN base in S Sudan.
About 1500-2000 rebels attacked the base where 43 Indian peacekeepers were present along with six UN police advisers and two civilians.
The United Nations Mission in South Sudan (UNMISS) said about 30 South Sudanese had sought shelter from the turmoil plaguing areas of Akobo County.
The UNMISS, in a statement, strongly condemned the attack. The UN has said there were reports of more casualties but did given any further details.
The mission said it is doing everything possible to ascertain the circumstances surrounding the assault on the base and secure the safety of its personnel who remain there. South Sudan has been in turmoil since President Salva Kiir accused his ex-deputy Riek Machar of mounting a coup.
The unrest, which broke out on Sunday, has killed some 500 people so far.
The conflict first erupted in the capital Juba but has since spread. Kiir, who is a Dinka, has blamed the violence on a group of soldiers who support Machar, a Nuer.
The president accused them of trying to take power by force on Sunday night in a coup attempt by Machar, a claim the former vice president denies.
UN Secretary-General Ban Ki-moon said he was "deeply concerned by reports of growing violence in many parts of South Sudan, human rights abuses and killings fuelled by ethnic tensions".
However, the government insists the clashes are over power and politics, noting that both sides involved in the clashes include leaders from different tribes.
"We condemn in strongest possible terms attempts to depict the coup as ethnic strife," a government statement said.