BANGKOK — At least 29 people, including children, have been killed in an artillery strike on a displaced persons camp in north-east Myanmar, near the Chinese border.

The camp is in an area controlled by the Kachin Independence Organization (KIO), one of several ethnic insurgent groups which have been fighting for self-rule for many decades.

All the victims were civilians, a KIO spokesman told the BBC.

It is one the deadliest attacks in the 63 year-long conflict in Kachin State.

Kachin officials say the armed forces have scaled up attacks on KIO-run areas over the past year because of growing Kachin support for other insurgent groups fighting the military government.

Much of Myanmar has been embroiled in a wider civil war since a 2021 military coup displaced the country's elected government. The military has increasingly used air strikes against opposition-controlled towns and villages since seizing power.

The exiled National Unity Government (NUG) has blamed the junta for the attack on the camp, describing it as a "war crime and crime against humanity".

Junta spokesman Major General Zaw Min Tun denied that the military was behind the attack.

He claimed the army does not have any operations in the area and said the destruction was "probably" caused by stockpiled explosives.

Images shared by local media showed bodies being pulled from the rubble and dozens of body bags lying side by side.

The attack late on Monday night happened in the Mong Lai Khet camp for displaced persons - on the outskirts of Laiza, the town on the Chinese border where the KIO has its headquarters.

Parts of the camp were destroyed by powerful explosions at around midnight, KIO officials told the BBC.

Footage of the aftermath shows many houses obliterated and large numbers of casualties.

Kachin officials believe at least 11 children are among those killed. Fifty-six more people were also injured in the latest attack, 44 of whom had been taken to hospital for treatment.

The United Nations in Myanmar said it is "deeply concerned" about reports of deaths in the camp.

"IDP camps are places of refuge, and civilians, no matter where they are, should never be a target," it said in a statement on Facebook.

The area around the camp has experienced conflict for many years, as it is not far from the front lines, where Kachin troops in trenches face off against government forces.

However, locals say that no fighting has taken place near the camp in recent times.

It is possible the attack was carried out from the air.

Almost exactly one year ago, the Myanmar air force used precision guided bombs to attack an open-air concert at another Kachin base in the night, killing more than 80 people.

The Kachin Independence Army (KIA) — the KIO's armed wing — is one of the largest and most powerful insurgent groups in Myanmar. It has been fighting the central government sporadically since 1960, and consistently since a ceasefire broke down in 2011.

Since the coup the military government has viewed the KIA as a significant threat, as it has been giving weapons and training to some of the new insurgent groups which have formed across the country to resist military rule.

KIA also has a long-standing alliance with the Arakan Army, an insurgent group formed initially in Kachin State. But since 2016 it has been operating in Rakhine State, on the other side of the country, where it has successfully challenged the military for control of much of the territory. — BBC