Human Rights Watch urged the government to allow humanitarian agencies access to tens of thousands of ethnic Kachin displaced by the fighting.
On January 14, 2013, at about 8:30am and 10.30pm, the Burmese army fired several 105 mm howitzer shells into Laiza, the administrative center of the rebel Kachin Independence Organisation.
The first attack struck the center of town, killing three civilians - an elderly Christian pastor, a 46-year-old displaced man, and a 14-year-old boy - and wounding several others.
In the nighttime attack, two shells struck property in a populated residential area but did not cause any casualties.
The shells in the first attack struck about one-half kilometer from a Kachin Independence Army military command center on the top floor of a hotel near the town's border with China.
Although the command center is a valid military target, Burmese government statements denying that the army shelled Laiza raise doubts that this was an intended target.
''Burmese President Thein Sein needs to order his army commanders to respect the laws of war and end unlawful attacks on civilians,'' said Phil Robertson, deputy Asia director at Human Rights Watch.
''Both the Burmese army and the KIA should take all necessary precautions to keep the tens of thousands of civilians in and around Laiza from harm's way.''
International humanitarian law, or the laws of war, which are applicable to both sides in the fighting in Kachin State, prohibits attacks targeting civilians and civilian structures.
The law also prohibits attacks that do not or cannot be directed at a specific military objective, and thus put civilians at risk.
Bombardments subjecting an entire town to attack because of the presence of military targets are likewise indiscriminate. The Burmese army's firing of howitzer shells with a large blast radius in a populated area also may have violated the prohibition against indiscriminate attacks.
Human Rights Watch said that the laws of war also require all parties to a conflict to avoid, to the extent feasible, deploying military forces within or near densely populated areas.
The KIA's placing of a command center within Laiza put civilians at unnecessary risk of attack.
Human Rights Watch urged the Burmese government and the KIA to take all necessary precautions to minimise loss of civilian life and property during military operations.
There are approximately 15,000 internally displaced people (IDPs) sheltering in camps established by the Kachin Independence Organisation and Kachin civil society groups in Laiza. The town has approximately 20,000 permanent residents.
On January 14, government spokesman Ye Thut denied that government shells struck Laiza. The previous week, the Office of the President publicly denied that the army conducted any airstrikes against the KIA with helicopters and fighter jets, but then later backtracked when news reports showed video footage of the attacks.
In December 2011, President Thein Sein sent a letter to the army chief of staff and military commands in northern Burma, requesting the army cease attacks in Kachin State unless acting in self-defense, yet there is little evidence the military is following that directive.
Background on the conflict
The Burmese government renewed hostilities against the KIA in June 2011 in a contested area surrounding a Chinese-owned hydropower dam, ending a 17-year ceasefire between the government and the Kachin Independence Organisation.
In 'Untold Miseries: Wartime Abuses and Forced Displacement in Burma's Kachin State,' Human Rights Watch described how the Burmese army attacked Kachin villages, shot and killed fleeing civilians, used torture during interrogations, committed rape, and pillaged properties.
As a result, tens of thousands of people have been displaced. The army also used antipersonnel mines and conscripted forced laborers on the front lines, including children as young as 14. The KIA has also used antipersonnel landmines and deployed child soldiers.
''Continuing abuses by the Burmese army in Kachin State should come as a sobering corrective to governments who believe that the changes going on in Burma are reaching the entire country,'' Robertson said.
There are approximately 90,000 IDPs in Kachin State, with approximately 60,000 residing in sizable camps in KIA-controlled territory along the border with China's Yunnan province.
The Burmese government has repeatedly denied humanitarian access to the United Nations and international aid groups seeking access to displaced people in KIA territory, creating a humanitarian emergency and leaving those displaced to rely on minimum amounts of assistance from the Kachin Independence Organisation and local civil society and community groups.
Now displaced for months and, in some cases, over a year, many of these displaced people are desperately in need of food, medicine, and medical attention, warm clothing and cooking materials, and adequate shelter, local aid workers told Human Rights Watch.
International humanitarian law holds parties to the conflict responsible for ensuring that the humanitarian needs of the war-affected populations are met. If the government is unable to meet this obligation fully, it must allow impartial humanitarian agencies to do so on its behalf.
The Burmese government should immediately ensure the freedom of movement of humanitarian relief personnel, with temporary restrictions allowed only in cases of military necessity.
''President Thein Sein should get the message that deliberately denying aid to tens of thousands of war-ravaged people in need is completely at odds with his government's self-appointed image as champions of rights and reforms,'' Robertson said.
''Concerned governments should demand an immediate end to Burma's systematic denial of humanitarian assistance in Kachin State.''