The Karen National Union (KNU) said Wednesday it was investigating whether Chinese nationals were among those killed and wounded in a military airstrike on a mine that it runs.

On Tuesday 15 November, the military clashed with fighters from the KNU near the Thai border, both sides said.

The military later carried out an airstrike on the Thabyu antimony mine run by the KNU, killing three people, wounding four and leaving at least eight missing, a KNU commander told AFP.

Locals said one of the dead was a Chinese citizen and that another had been wounded, media reported.

The KNU commander said around 200 Chinese nationals were involved in on-site operations at the Thabyu mines and that the group was "still investigating" whether any were among the dead or missing.

Analysts say many areas along Myanmar's lawless eastern border are awash with Chinese investment, including in casinos, mines and logging.

The junta said it had carried out an "operation" on the mine, without specifying what this was.

It said the KNU was carrying out "subversive acts" by "illegally" operating the mine.

"We saw the news that some foreigners were killed," junta spokesman Zaw Min Tun said in response to questions on the attack on the mine.

"If so, they are just illegal people working illegally."

China is one of the Myanmar military's few international allies and has refused to label the power grab that ousted Aung San Suu Kyi's government a coup.

A Chinese government spokeswoman told a regular press briefing on Wednesday that she had no information on reports of the attack on the mine.

AFP