Two U.N. peacekeepers from Ethiopia killed in South Sudan ambush

Among the injured were three U.N. peacekeepers, two police officers from South Sudan and two civilian staff members, U.N. spokesperson Stephane Dujarric told a press briefing.

He said the attack was carried out by unidentified gunmen and the patrol appeared to have been deliberately targeted.

"These are part of regular patrols that the U.N. has been doing in trying to help the constant insecurity in the area," Dujarric said.

The U.N. has called on relevant authorities for a thorough and prompt investigation to ensure all those responsible are brought to justice, Dujarric said. He stressed that "attacks against U.N. peacekeepers may constitute war crimes under international law."

The latest violence "brings to nine the number of peacekeepers killed in malicious acts since January 1 of this year," he added.

Attacks on U.N. personnel are rare but not unprecedented in South Sudan, where U.N. patrols operate in volatile areas affected by intercommunal fighting, armed youth mobilizations and clashes involving government forces.

In June, the U.N. Security Council adopted a resolution aimed at strengthening accountability for attacks on U.N. peacekeepers, amid concern over rising violence and low prosecution rates.

That followed a series of incidents targeting U.N. personnel, including the killing of seven peacekeepers serving with the United Nations Interim Force in Lebanon after a fresh round of fighting broke out between Israel and Hezbollah in early March.

(Reporting by David Brunnstrom; editing by Susan Heavey, Rosalba O'Brien and Bill Berkrot)