By Michelle Nichols

UNITED NATIONS (Reuters) – Russia and China abstained in a U.N. Security Council vote on Friday to extend a U.N. peacekeeping mission in the Central African Republic (CAR) as the United States called on Russia to investigate accusations of abuse by Russian contractors in the country.

Russia has sent hundreds of military instructors to the CAR – a gold- and diamond-rich country of 4.7 million people mired in violence – to train the army, police, and national gendarmerie as Moscow works to expand its influence in Africa.

Earlier this year, U.N. experts accused the Russian instructors and CAR troops of targeting civilians with excessive force, indiscriminate killings, occupation of schools and large-scale looting. The Kremlin has denied accusations.

“We would like to call attention to the use of the phrase ‘all parties to the conflict’ in the resolution, which in our view, includes these Russian contractors – they must respect international humanitarian law and it is imperative that they respect the human rights of all Central Africans,” said deputy U.S. Ambassador to the United Nations Richard Mills.

Mills said Washington called on both the Central African Republic and Russian governments to fully investigate accusations of abuse and to hold those responsible accountable.

“Again and again, we hear from a number of council members unfounded egregious accusations regarding our specialists that we have rejected on several occasions,” deputy Russian U.N. Ambassador Anna Evstigneeva said.

“If there have been violations, then they should be investigated primarily by the national authorities in the CAR. We are in bilateral contact with them and we coordinate work with them,” she told the council.

While Russia and China said they support the U.N. peacekeeping operation, which was established in 2014, they abstained because the Security Council resolution did not reflect concerns expressed by the CAR government.

The relationship between the CAR government and the U.N. mission, known as MINUSCA, is strained. MINUSCA has accused security forces of repeatedly violating an agreement between them. MINUSCA has some 12,000 troops and 2,000 police.

(Reporting by Michelle Nichols; editing by Jonathan Oatis)