Central African Republic authorities have opened an investigation into the deaths of nine Chinese nationals killed in an attack on a gold mine, the state prosecutor's office told AFP on Monday.
The nine died in an as-yet unclaimed attack in the centre of the country on Sunday.
"An enquiry was opened as soon as we knew an attack had taken place," said Manasse Wankian, prosecutor at Bambari, the main town in Ouaka prefecture, close to where the attack happened.
Chinese President Xi Jinping earlier Monday called on Bangui to "severely punish" the killers.
Xi "has given important instructions, demanding 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", a foreign ministry spokesperson said in Beijing.
Two people were seriously wounded, China added.
The CAR, one of the world's poorest countries, has been in the throes of civil conflict since 2013.
Militias hold sway over large tracts of the country, and often clash over access to minerals and other resources.
Bambari's deputy prefect, Saturnin Nicaise Ngrepande, told AFP that government forces "and Russians have been here since yesterday... they have gone off to hunt for the rebels, whose identity has yet to be confirmed."
"It could be members of the Union for Peace in Central Africa" (UPC), he said, referring to a major rebel group.
"But it could be hard to know whether it's a (UPC) group that's attached to the Coalition of Patriots for Change" (CPC), he said.
The CPC is an alliance of rebel groups created in December 2020 to overthrow President Faustin Archange Touadera.
Prime Minister Felix Moloua on Sunday accused the CPC of the attack, but offered no evidence.
In a statement, the CPC denied any involvement in what it described as a "despicable and barbaric" act.
It accused Russia's Wagner mercenary group of being behind the deed, also without providing evidence.
Russian paramilitaries deployed to the CAR in 2018. Their numbers increased in 2020 to fend off an assault on the capital by the CPC.
The nine had been employed at Gold Coast Group gold mine 25 kilometres (15 miles) from Bambari.
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 AFP journalist said.