Ethnic Kachin rebels in northern Myanmar say the government is keeping up air and ground attacks against them despite international calls for restraint.
An exclusive video obtained by Al Jazeera on Tuesday reportedly shows government air raids on an area controlled by Kachin fighters.
Pointing to the latest skirmish near the northern city of Laiza, Al Jazeera's Wayne Hay says that "there is no sign that this fighting is slowing down anytime soon.
"There is some feeling that perhaps the Myanmar military is launching an attempt to take that town, which of course would be a severe blow to the Kachin Independence Army (KIA)".
Laiza, which is near the border with China, and a government base are close to each other, and access to both is by the same road.
In a statement sent to Al Jazeera, the Myanmar government confirmed that the air force "conducted some ground support operations" around the government base.
"These operations are to clear the surrounding hills where KIA troops using to shell and attack Army Lajayan Camps for past months," the statement reads.
"Army never intend to attack or occupy Laiza. All operations are self defense for troops stationed at Army Lajayan Camp."
On Monday, a spokesman for the rebel fighters claims that government troops used fighter jets and helicopters in the aerial attacks.
"Launching attacks against important KIA hill posts and occupying these outposts amounts to launching attacks against Laiza,'' La Nan said Monday.
The government has said several times it has no intention of trying to seize Laiza.
The Kachin, like Myanmar's other ethnic minorities, have long sought greater autonomy from the central government.
They are the only major ethnic rebel group that has not reached a truce with President Thein Sein's elected government, which came to power in 2011 after almost five decades of military rule.
Intermittent fighting escalated last month when the rebels rejected a government demand that they allow supply convoys to reach an army base.
The Kachin stage attacks on government convoys trying to get through to the base, saying the supplies include ammunition that could be used to try to take their headquarters.
The army claims its actions are in self-defense, a response to the Kachin blocking the road.
The US and China are among those parties urging an end to the fighting.
"Our view is that all sides need to cease and desist and get into dialogue with each other,'' Victoria Nuland, the state department spokesperson, said last week.
Source: Al Jazeera and agencies