The UN Security Council on Wednesday condemned the reported killing of at least 35 people, including four children and two humanitarian workers in Myanmar's Kayah State on 25 December.
The Ambassadors in a statement called for accountability and "the immediate cessation of all violence".
The Council members emphasised the importance of respecting human rights and ensuring the safety of civilians. They also underscored the need for "safe and unimpeded humanitarian access to all people in need, and for the full protection, safety and security of humanitarian and medical personnel", according to UN News.
The Ambassadors reaffirmed their support for the people of Myanmar and the country's democratic transition along with their strong commitment to the sovereignty, political independence, territorial integrity and unity of Myanmar.
Credible reports suggested that four children were killed, including two 17-year-old boys, a teenage girl and a child approximately age five, whose gender was not mentioned, the UNSC said in a statement.
The two humanitarians worked for the non-Governmental organization (NGO) Save the Children, which confirmed their deaths. They were killed while returning to NGO's Loikaw office after responding to humanitarian needs in a nearby community, it added.
Earlier in the week, the UN Children's Fund (UNICEF) condemned the killings, saying it was "shocked and saddened" by the reported killing and burning of victims during a time when many prepared to celebrate Christmas.
In a statement, the UNICEF Regional Director for East Asia and the Pacific, Debora Comini, condemned the attack.
She reminded that the protection of civilians - particularly children and humanitarian workers - must be treated as a priority during times of conflict, in accordance with international humanitarian law and the Convention on the Rights of the Child, to which Myanmar is a signatory.
"UNICEF calls for urgent action to investigate this deplorable incident and to hold those responsible to account," she said.
"We offer our deepest condolences to the families of the victims and to our colleagues at Save the Children".