At least nine Chinese mine workers were killed when a group of armed men attacked them in the Central African Republic (CAR) Monday.

The incident sparked a rare call from China's President Xi Jinping for the perpetrators to be "severely" punished.

The attack by "armed men" happened at about 5 a.m. local time near Bambari, said the central town's mayor, Abel Matchipata.

Matchipata told AFP that "nine bodies and two wounded" had been counted, adding that the victims were Chinese workers at a site run by the Gold Coast Group, 25 kilometers (15 miles) from his town.

China's Foreign Ministry confirmed the toll and Xi called on authorities in the Central African Republic to "severely punish" those behind the killings.

The president had ordered "an all-out effort to treat the wounded, handle the aftermath in a timely manner, severely punish perpetrators in accordance with the law, and ensure the safety of Chinese citizens," an unnamed China Foreign Ministry spokesperson said in a statement.

Local authorities did not release further details of the attack, nor was there any claim of responsibility.

The victims' bodies were transferred to a hospital in the capital Bangui, where Chinese Ambassador Li Qinfeng and CAR Foreign Minister Sylvie Baipo Temon attended, an Agence France-Presse (AFP) journalist said.

Civil conflict has hit the Central African Republic, one of the world's poorest countries, since 2013, when armed groups ousted President Francois Bozize.

In a statement Sunday, the Coalition of Patriots for Change (CPC), an alliance of rebel groups created in December 2020 to overthrow President Faustin Archange Touadera, denied any involvement in the attack.

The group denounced the "despicable and barbaric" act, accusing the Russian Wagner mercenary group of being behind the killings.

In 2020, President Touadera called on Moscow to come to the aid of his debilitated army, after armed groups took control of two-thirds of the country and began an assault on Bangui.

Hundreds of Russian paramilitaries then joined the few hundred already present since 2018, repelling the rebel offensive and pushing them out of a large part of the territories and cities they controlled.

Wagner is among the most prominent Russian groups present in Africa, as well as playing a large role in other conflicts, such as Moscow's invasion of Ukraine.

Xi is visiting Russia this week as Beijing seeks to claim a peacemaking role in that conflict, though Western countries have said Beijing may provide arms to Moscow.

China and Russia are bolstering their presence in Africa to tap its rich natural resources, analysts say, despite grave warnings from U.N. agencies that the world's poorest countries face accumulating crippling debts.

"One out of every three major infrastructure projects in Africa is built by Chinese state-owned enterprises, and one out of every five is financed by a Chinese policy bank," Paul Nantulya of the Africa Center for Strategic Studies, an academic institution within the U.S. Department of Defense, told AFP.