By Carl Odera
JUBA (Reuters) - Three crew members of a U.N. peacekeeping helicopter in South Sudan were killed on Tuesday when their aircraft crashed on a routine cargo flight, and a fourth crew member was being treated for injuries, the United Nations said.'
Russia's Interfax news agency said "preliminary information" indicated the helicopter, operated by a Russian firm, had been shot down as it flew over an area that has been a flashpoint during a civil conflict that is now more than eight months old.
The U.N. Mission in South Sudan (UNMISS) said an investigative team would arrive at the crash site tomorrow. It had no immediate comment on the Russian report.
The Mi-8 helicopter crashed about 10 km (6 miles) south of Bentiu, the capital of oil-producing Unity State, which lies in the north of the Africa's newest nation, the UNMISS said.
Fighting has often flared in Unity State as rivals battle to control vital oil fields. The conflict has pitted soldiers loyal to President Salva Kiir against the former deputy president, Riek Machar. Despite two ceasefire pacts, fighting has continued.
Toby Lanzer, the officer-in-charge of UNMISS, said the helicopter, which was contracted to the U.N. mission, had been flying from Wau in the southwest to Bentiu in the north.
"According to preliminary information, it was shot down by unknown (people) in a combat zone," Interfax quoted an unnamed source as saying. The helicopter was owned by Russia's UTair company, the agency said.
All three of those killed were Russian, U.N. spokesman Stephane Dujarric said in New York.
The U.N force, set up after South Sudan's independence in 2011, has been seeking to protect civilians. At least 10,000 people have been killed in the fighting, which has driven the nation to he brink of a "man-made" famine.
Peace talks in Ethiopia have made little significant progress. The United States and European Union have imposed sanctions on commanders from both sides and regional African states sponsoring negotiations have threatened punitive measures against those impeding talks, but to little avail.
Initially set up to protect civilians as well as carry out other state-building work, the UNMISS peacekeepers were authorised by the U.N. Security Council in May to focus on protecting civilians and backed the use of force.
UNMISS has an approved strength of up to 12,500 military personnel and more than 1,300 civilian police personnel.
(Additional reporting by Louis Charbonneau in New York and Gabriela Baczynska in Moscow; Writing by Edmund Blair; Editing by Alison Williams and Susan Fenton and Larry King)