U.N. deputy special envoy Toby Lanzer told the mission's Radio Miraya violence had died down in South Sudan's capital, Juba, after two days of heavy fighting. He said "thousands" of people were seeking refuge in UNMISS camps set up in the capital city.
"There were civilians who were caught in the crossfire [and] seriously wounded," he said.
South Sudanese President Salva Kiir accused his former Vice President Riek Machar of attempting a coup earlier this week. Machar was sidelined in a Cabinet reshuffling earlier this year.
The U.S. State Department issued a travel warning Tuesday for South Sudan. The British Foreign and Commonwealth Office followed suit Wednesday, adding it decided to withdraw its diplomats and their dependents from Juba as a security precaution.
Felicity Gapes, a delegate from the International Committee of the Red Cross working from Juba, said in a statement Tuesday healthcare officials were working around the clock to provide assistance to those in need.
The ICRC didn't provide an indication of how many were killed in the violence but said it was prepared for a heavy influx of patients.