Myanmar's security forces have killed more than 1,000 civilians since the military ousted Aung San Suu Kyi from power six months ago, an advocacy group said on Wednesday.

The country has been in turmoil since February 1, when the armed forces seized power in a lightning coup, triggering dissent as protesters demanded a return to democracy.

Security forces responded with bloody crackdowns, using live rounds against civilians. But anti-junta mobs -- some of whom have formed self-defence groups -- are still taking to the streets daily in flash marches.

Activist group Assistance Association for Political Prisoners -- which verifies the deaths and mass arrests under the regime -- said the number of people killed by security forces reached 1,006 on Wednesday.

"As long as the military is in power, they will continue to kill youths, professionals like doctors and teachers, men, women and children," AAPP's joint secretary Ko Bo Gyi said.

"They are not only killing our lives but the country's future and democratic hopes."

Ko Bo Gyi -- whose group has been named an "unlawful" organisation by the junta and is currently in hiding -- also accused authorities of "weaponising" Covid-19 as the country weathers a deadly surge.

So far, Myanmar has recorded more than 363,000 cases and 13,786 deaths from Covid.

The health crisis has been aggravated by a lack of formal medical care as many hospitals have been emptied of staff joining nationwide strikes against the junta.

Patients are also reluctant to go to military-run hospitals, creating long lines for oxygen and medical supplies in pharmacies across Yangon.

The junta has repeatedly justified the coup by alleging widespread fraud in last year's election, and given much lower civilian death tolls.

Authorities also said in June that more than 90 members of the security forces have been killed in clashes.

Deposed leader Suu Kyi is facing a raft of criminal charges, from possessing illegal walkie-talkies to violating the state secrets act.

Army chief Min Aung Hlaing was installed as the prime minister of a "caretaker" government, which the junta has dubbed the State Administration Council.

Photo: Protesters hold up the three-finger salute during a demonstration against the military coup in Yangon. Photo: AFP