The Burmese Air Force conducted on Sunday an air strike on a village in the separtist-controlled region of Kachin during a concert, killing at least 50 people, mostly civilians, the Irrawaddy news portal reported on Monday.

The concert was held by the separatist Kachin Independence Army (KIA) to commemorate the anniversary of the founding of the Kachin Independence Organization (KIO).

The Air Force carried out the airstrike at around 8:30 PM local time on Sunday, targeting an outdoor theater near the city of Hpakant where a concert was taking place marking the KIO's anniversary. The organization has been fighting for the autonomy of the Kachin State in Myanmar's north.

Though the airstrike killed several high-ranking  KIA officers, it mostly killed civilians while injuring as many as 100 others, the news portal reported.

"The hatred felt by the Kachin people for the military has just soared. The revolution will therefore only get stronger. The Kachin people and KIA will redouble their efforts in the Spring Revolution to uproot the military dictatorship," KIA/KIO spokesperson Colonel Naw Bu told Irrawaddy.

With 62 years since its founding, the KIO was established in 1960 to safeguard the rights of the Kachin people, which are an ethnic minority group within Myanmar, and to fight for broad autonomy for the state they live in.

The KIA, on the other hand, is KIO's military wing. It has been fighting the Burmese government since the 1960s. Years after Myanmar gained independence from the United Kingdom in 1948, in the 1960s, the central authorities and the military groups of national minorities waged a civil war in the country until the 1990s.

The new escalation of the civil war has been taking place since the military took over in February 2021, experts believe, expecting that there would be further violence between the two warring sides.

The army took the power from former Myanmar State Counselor Aung San Suu Kyi, and she was tried for corruption earlier in the year and sentenced to five years in jail.

Suu Kyi has faced a torrent of criminal charges since a military coup toppled her administration in February last year, throwing the country into instability.

Some members of the "opposition" government led by Aung San Suu Kyi's toppled administration had their citizenship revoked, Myanmar's junta announced in March.

Ousted politicians created the so-called National Unity Government weeks after the military took power last year, vowing to overthrow it.

Suu Kyi, nominated to lead the organization, has been arrested since the coup and is facing allegations that could land her in prison for more than 150 years.