BANGKOK: At least 29 people, including women and children, were killed in Myanmar in an artillery strike on a refugee camp near the border with China which sources said was carried out by the ruling military. The attack was one of the deadliest on civilians since the military seized power in a 2021 coup, which triggered conflict with a resistance movement and armed ethnic groups across the country. The shadow National Unity Government and the British Embassy in Yangon blamed the military for the shelling, which took place close to midnight on Monday in Kachin State. A spokesperson for the junta said the military was not responsible. “We are investigating. We always take care of border peace situation,” Zaw Min Tun said, adding that the explosion may have involved an ethnic rebel group’s own munitions. Sources said artillery hit a camp for internally displaced people about 5 km (3 miles) from a base in the town of Laiza run by the Kachin Independence Army (KIA), which has been in conflict with Myanmar’s military for years. About 30 people were killed, according to sources and media. A spokesperson for the KIA called it a “massacre against our ethnic people,” according to Myanmar Now. The NUG condemned what it called a vicious attack on civilians and said the world must put Myanmar’s generals on trial. “This act of military council is war crime and crime against humanity,” NUG spokesperson Kyaw Zaw said, adding an attack at the border with China showed the junta did not respect its neighbor’s demand for peace and stability. The British Embassy also blamed the military for the strike, adding it “must stop its brutal campaign against the Myanmar people.” The US was “deeply concerned” by the reports, State Department spokesperson Matthew Miller said in a statement. “We strongly condemn the military regime’s ongoing attacks that have claimed thousands of lives since the February 2021 coup and continue to exacerbate the region’s most severe humanitarian crisis,” Miller said. United Nations Secretary-General Antonio Guterres said those responsible “must be held to account” and called on Myanmar’s neighbors to leverage their influence to stem “the military’s intensifying attacks throughout the country, which continue to fuel regional instability,” according to a spokesperson. China’s Foreign Ministry called on “relevant parties to resolve disputes peacefully, ... avoid escalation, and take practical and effective measures to ensure the security of the China-Myanmar border.” Laiza sits close to the Chinese border and is home to many civilians living in displacement camps in and around the town. The UN says more than a million people have been displaced by the conflict in Myanmar. A student activist currently in Laiza said the whole town was “shaken” by the explosion and residents were evacuating. “We are on alert because we worry that there can be second bomb attack,” said Justin, who declined to provide a last name. “The locals are worried about that and so people are relocating now.” Photographs shared with and verified by Reuters showed residents in Laiza preparing to bury dozens of victims in coffins laid out next to rows of freshly dug graves. Kachin media shared a series of graphic images on Facebook of destruction, which could not immediately be verified by Reuters. One showed casualties on the floor, another more than a dozen body bags lined up. Others showed men in military dress sifting through wreckage and a man carrying the body of a small child. The incident was the deadliest since an air strike in Myanmar’s volatile Sagaing region in April that killed scores of people including civilians. Khon Ja, an activist with the Kachin Peace Network Civil society group, told Reuters she had visited the local hospital and was told 29 people were dead and 59 wounded. “The bomb was too strong ... the village was totally destroyed and disappeared,” she said.