The United Nations (UN) peacekeepers from Nepal serving in South Sudan are facing allegations of child rape, reported AFP.

Nepal at the request of the UN has agreed to send a team of investigators to work with the UN office of internal oversight on the case.

UN spokesman Stephane Dujarric on Monday said that the case was "especially heinous."

"Any act of sexual abuse is horrendous," said UN spokesman Stephane Dujarric. "One involving a child is especially heinous."

According to the AFP report, the allegations were received on April 13 and involve Nepali troops serving in the UN mission in South Sudan who allegedly raped two teenage girls, UN officials said. It remains unclear how many Nepali soldiers are involved.

The United Nations has deployed 14,800 troops and police in South Sudan, with a mandate to protect civilians caught up in a brutal war between President Salva Kiir's forces and rebels.

Earlier, in February, 46 UN peacekeepers from Ghana were recalled from their base in northwestern South Sudan after the mission received allegations of sexual exploitation of women.

UN Secretary-General Antonio Guterres has vowed to toughen the UN response to allegations of misconduct against the blue helmets, whose mission is to protect vulnerable civilians in conflict zones.