JOHANNESBURG (Reuters) - South Africa’s military has opened an investigation into reports that members of its 1,000-strong, U.N.-mandated peacekeeping contingent in eastern Democratic Republic of Congo assaulted and tortured locals.

A military statement said “corrective actions” would ensue if the reports, which it understood had come from Congolese citizens, were found to be true.

The U.N. peacekeeping mission in Congo, MONUSCO, has received four allegations of misconduct, including three allegations of sexual exploitation involving adult victims, U.N. spokesman Stephane Dujarric said on Monday.

“The fourth allegation refers to physical violence inflicted by military peacekeepers on a 17-year-old boy in eastern Kasai. The victim was referred to UNICEF (United Nations Children’s Fund),” Dujarric said.

He said the United Nations had requested that the investigations by South Africa be completed within 90 days.

The inquiry would be conducted in liaison with the MONUSCO mission in Congo, the South African statement said.

“We are aware of the case and we have the police record,” MONUSCO spokeswoman Florence Marshall said.

Under bilateral agreements with host countries, U.N. soldiers found to have committed crimes while serving in peacekeeping missions are judged and punished in their home jurisdictions.

Congolese government spokesman Lambert Mende said he was not aware of the alleged abuses but added that it was “completely normal” that the investigation would be carried out by South African, rather than Congolese, authorities.

Established in 2000, MONUSCO is the United Nations’ largest peacekeeping mission and has come under increasing political and military pressure as the United States has threatened to cut funding just as militia activity in Congo’s mineral-rich eastern hinterlands has stepped up.

Much of the increase in insecurity is linked to political tensions surrounding President Joseph Kabila’s refusal to step down when his mandate expired at the end of 2016.

An election to replace Kabila, who has ruled Congo since his father’s assassination in 2001, has been repeatedly delayed and is now scheduled for December 2018.

Suspected Ugandan rebels killed at least 15 Tanzanian U.N. peacekeepers and wounded 53 others in a raid on a base in December. U.N. Secretary-General Antonio Guterres condemned it as the worst attack on the organization in recent history.

The South African contingent, based in Goma on the Rwandan border, is part of MONUSCO’s Force Intervention Brigade, which has a special beefed-up mandate to “neutralize and disarm” guerrilla groups.