Forty-six UN peacekeepers from Ghana have been recalled from their base in northwestern South Sudan following allegations of sexual exploitation of women sheltering at the site, a UN spokesman said.

The 46 police were confined to barracks in Juba on Saturday after a preliminary investigation showed that the Ghanaians were "engaging in sexual activity with women" living at a UN site to protect civilians in Wau, UN spokesman Stephane Dujarric said.

"The information received indicates that some members of the formed police unit allegedly engaged in transactional sex," he added.

Full investigation

The UN peacekeeping mission in South Sudan has a "zero tolerance, no excuses, and no second changes approach to sexual exploitation and abuse," he said.

Ghana is cooperating with the United Nations to carry out a full investigation of the complaint received on February 8, the spokesman added.

Under UN rules, it is up to troop-contributing countries to take action against their nationals accused of misconduct while serving under the UN flag, but the United Nations carries out joint investigations with the national authorities.

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.

Youngest nation

The United Nations has 7,000 troops and 900 police in its UNMISS mission. About 200,000 South Sudanese are sheltering at UN sites protected by UNMISS peacekeepers.

The world's youngest nation which achieved independence from Sudan in 2011, South Sudan descended into war in December 2013 when President Salva Kiir accused his former deputy Riek Machar of plotting a coup.

Tens of thousands of people have been killed and nearly four million South Sudanese displaced from their homes.