Since the army seized power on February 1 and removed the elected government of Aung San Suu Kyi, the security forces have put down protests opposing military rule.

In response, groups of opponents of the coup known as people's defence forces have sprung up across Myanmar.

Until now, fighting involving lightly armed militias has been mainly confined to small towns and rural areas, but a group claiming to be Mandalay's new People's Defence Force said its members responded after the army raided one of its bases.

"The fight has started. There will be more fights," a member of the militia identified as Captain Tun Tauk Naing said by telephone on Tuesday.

About 20 soldiers had carried out the raid on the group sparking a gunfight with the military, which deployed three armoured cars to the area, Myanmar Now reported.

Another militia official told the Mizzima news portal that six of its members had been arrested and two soldiers had been killed.

A spokesman for the junta did not answer calls seeking comment.

The army-owned Myawaddy Television, in a report on its Telegram message channel, said security forces had raided a house and "armed terrorists" had fought back with small weapons and bombs.

It said four "terrorists" had been killed and eight arrested while some security forces were seriously hurt.

In earlier incidents in other parts of Myanmar, the army has responded with artillery and air strikes after militia groups launched attacks on soldiers, with casualties on both sides and tens of thousands of people displaced from their homes.

The United Nations General Assembly on Friday called for a stop to the flow of arms to Myanmar and urged the military to respect the results of a November election and release political detainees, including Suu Kyi.

Security forces have killed at least 873 protesters since the coup, according to the Assistance Association for Political Prisoners activist group. The junta disputes that figure.

Australian Associated Press