The United Nations has called for an immediate end to clashes between Myanmar troops and ethnic Kachin rebels, as hundreds of civilians remain trapped in a remote area with limited food and shelter.
Skirmishes have affected at least 2,300 people in the Bhamo-Mansi area, including many who had already been displaced by previous fighting, the UN said Monday in a statement from Yangon.
The UN expressed particular concern for an estimated 700 students whose boarding school was surrounded on the weekend by Myanmar troops.
"These students and their teachers... were surrounded and blockaded inside the school compound but an appeal by the Catholic Church led to their release" later that evening, the UN said.
The UN called for an "immediate cessation of hostilities" to allow humanitarian access to displaced persons.
Fighting in Kachin, near the northern border with China, erupted in June 2011 when a 17-year ceasefire crumbled. It has displaced approximately 100,000 people.
Along with religious unrest elsewhere in the country, the Kachin conflict has overshadowed widely praised political changes as Myanmar emerges from decades of military rule.
President Thein Sein's reformist government has reached tentative peace deals with most major ethnic minority rebel groups in the country, which has been racked by civil wars since independence from Britain in 1948.
Despite talks, peace in Kachin has so far remained elusive, thwarting government efforts to cement a nationwide ceasefire that would burnish its reform credentials.
Speaking in Yangon, the Kachin Independence Army's second-in-command confirmed that clashes took place around the school in Nam Lim Pa village near the Chinese border.
General Gum Maw said Myanmar troops entered the area with a relief convoy and "fighting broke out."
"The fighting has been on and off. They were fighting yesterday [Sunday] and also today as they are close to our forces," he told reporters, noting the clashes would not derail the tentative peace process, with talks between the government and an umbrella organisation representing several ethnic groups scheduled for December.