JUBA, South Sudan - United Nations peacekeepers abandoned their posts when fighting erupted in South Sudan's capital in July and then used tear gas on frightened civilians who sought shelter at the centre of the U.N. base, a new report says.

Wednesday's report by the U.S.-based Center for Civilians in Conflict adds to a growing list of incidents where U.N. peacekeepers have been accused of failing to carry out their mandate in South Sudan, where civil war erupted in December 2013.

More than 12,000 U.N. peacekeepers are in this East African country. More than 200,000 civilians are sheltering in U.N. camps in the capital and elsewhere.

The new report, based on interviews with 59 South Sudanese civilians and 21 officials with the U.N. mission, among others, says some peacekeepers refused orders to protect civilians during the July chaos in Juba. Hundreds of people died in the fighting between government and opposition forces.

Peacekeepers with the U.N. force in South Sudan, or UNMISS, largely remained confined to their base during and immediately after the violence, and struggled to patrol the capital for weeks afterward, the report says.

The Associated Press has reported that peacekeepers also refused to respond to pleas for help as government soldiers looted and raped aid workers at the nearby Terrain compound.

Separately, the new report found that Chinese peacekeepers at a U.N. camp "fled en masse" from their positions in response to heavy fighting nearby, leaving behind some weapons and ammunition.

With those peacekeepers gone, and with nowhere in that part of the U.N. camp to seek shelter from gunfire, about 5,000 civilians "fled over fences and barbed wire" into the heart of the camp where administrative offices are located, the report says. Overwhelmed peacekeepers then struggled to manage the crowd, and civilian witnesses said some looting occurred.

A response came the next day.

"According to seven independent witness accounts, on the morning of July 12, UNMISS fired tear gas on the civilians with little or no warning," the report says.

In response to questions from the AP, a spokeswoman for the U.N. mission, Yasmina Bouziane, said two tear gas shells were used by peacekeepers to assure the safety of U.N. personnel, and there were no injuries. She also that in response to some direct and indirect heavy fire, some peacekeepers took cover as a self-defence measure.

Two Chinese peacekeepers died during the July fighting, and six others sustained major injuries.

The new report raises concerns that peacekeepers have been unable to learn from past mistakes.

After South Sudanese government soldiers in February attacked a U.N.-protected camp in Malakal that sheltered 48,000 civilians, a report by U.N. Secretary-General Ban Ki-Moon found that peacekeepers had a "lack of a proactive mindset" for civilians and experienced "confusion with respect to command and control and lack of co-ordination."

"There is very little accountability for peacekeeping failures in terms of protection of civilians," Matt Wells, a senior adviser on peacekeeping at the Center for Civilians in Conflict, told The Associated Press. "As long as there is little consequence to failing to perform under a mandate, events like Malakal and Juba are unfortunately likely to happen again." His organization advocates for protecting civilians in conflicts around the world.

At the same time, South Sudan's government has repeatedly hampered the U.N. mission, according to a recent confidential letter from the U.N. chief to the U.N. Security Council.

The U.S. ambassador to the United Nations, Samantha Power, said during the council's recent visit to the country that she had "never seen a mission that is as obstructed as UNMISS in its movement."

In August, the Security Council warned South Sudan's government to accept 4,000 additional peacekeepers and remove restrictions on the U.N. mission or face an arms embargo.

On Wednesday, Martin Elia Lomoro, South Sudan's minister of Cabinet affairs, told the AP that the government had accepted the force in principle, and that most of the deployment's technical areas had been agreed to.

"If you insist on bringing 4,000, OK. Let's see what they are going to do," Lomoro said.

News from © The Associated Press, 2016