Myanmar army dropped 'vacuum bomb' on opposition gathering: HRW

The Myanmar military launched a "vacuum bomb" attack on a gathering of opposition groups that killed more than 160 people, including children, said the Human Rights Watch.

A "vacuum bomb" disperses explosive material as a vapor cloud that uses atmospheric oxygen as a fuel when it is detonated. 

The airstrike on 11 April caused indiscriminate and disproportionate civilian casualties in violation of international humanitarian law, and was an apparent war crime, observed the human rights organisation.

It said foreign governments should prevent funding, arms, and aviation fuel from going to Myanmar's military, which continues to commit serious abuses with impunity.

"The Myanmar military's use of a weapon designed to cause maximum deaths in an area crowded with civilians shows flagrant disregard for human life," said Elaine Pearson, Asia director at Human Rights Watch. 

About 300 residents from Kantbalu township gathered on 11 April, ahead of the Buddhist new year to open an opposition-controlled administrative office in Pa Zi Gyi. 

Two witnesses told Human Rights Watch that at about 7:30am, a military jet flew overhead and dropped at least one munition, which exploded amid the crowd gathering around the building. 

Within minutes, a witness said, a helicopter gunship followed and fired cannons, grenades, and rockets into the crowd as people tried to flee.

A resident of Pa Zi Gyi said that members of the People's Defense Forces (PDF), an anti-junta militia, were at the opening. The office was intended for civilian uses such as filing taxes, township meetings, and judicial processes. 

The witness said the PDF stored goods, funds, and medicines in the office, but also some ammunition.

"The event agenda had meetings, entertainment, and awards ceremonies," the witness said. 

"There were many scouts and guards for security, but they were mainly concerned about possible junta military convoys on the road and not so much about airstrikes, so were taken by surprise." He said some of his family members including a child were killed in the attack.

A second witness said, "I got there early, and I was standing outside the building when the attack started so I had a chance to run for cover." He said he jumped into a trench just as a munition detonated near the building. "The first strike was by [a jet plane] that killed everyone inside and destroyed the building. But the subsequent strafing by [a helicopter] that came afterward … attacked and killed the survivors who were running for their lives into the nearby forest."

Human Rights Watch reviewed 59 photos of the victims' bodies and a video of the site following the attacks, and concluded that the initial strike was conducted with a large, air-dropped "enhanced-blast" type munition. 

Enhanced-blast weapons are more powerful than conventional high-explosive munitions of comparable size and inflict extensive damage over a wide area, and thus are prone to indiscriminate use when used in populated areas, Human Rights Watch said.

Human Rights Watch also reviewed eight photographs and two videos of the remnants of the weapons posted online and that the opposition National Unity Government (NUG) presented during a news conference on April 14. Human Rights Watch could not positively identify all of the remnants. However, some were consistent with the types of weapons and munitions used by the type of helicopter gunship, an Mi-35, deployed by Myanmar's military.

On state media on the evening of 11 April, the Myanmar military claimed responsibility for the airstrikes. 

A military spokesman, Zaw Min Tun, said they targeted People's Defense Force members and that the casualties were a result of the strikes hitting PDF storage units for explosives and landmines, which then exploded.

The National Unity Government said those killed were mainly civilian residents of Pa Zi Gyi, including 40 children. The youngest victim was 6 months old and the oldest was 76. As of 5 May, the NUG said a total 168 people had been killed in the attack. Human Rights Watch was not able to confirm those figures.

The Association of Southeast Asian Nations (ASEAN) should at its next meeting in Indonesia from 9-11 May signal its support for stronger measures to cut off the military's cash flow and press the junta for reform, said the Human Rights Watch.

It also urged the United Nations Security Council to follow up on its December resolution on Myanmar and its March follow-up briefing by urgently considering a new resolution to deter the military from committing further abuses, including adopting an arms embargo, referring Myanmar to the International Criminal Court, and imposing targeted sanctions on junta leadership and military-owned companies.

"The Myanmar junta's abusive military operations depend on its ability to purchase weapons and materiel," Pearson said. 

"ASEAN and the UN Security Council both need to reconsider their toothless approaches to Myanmar's junta and take stronger measures."