YANGON, Burma/Myanmar (AP) — Ethnic Kachin rebels in Burma said clashes in the country’s north continued Saturday despite a government promise to cease fire, casting doubt over hopes that the bloody conflict there could end soon.

Burma’s military had declared Friday it would stop attacks against rebels around the town of Lajayang, near Burma’s northeastern border with China, starting Saturday morning because it had achieved its goal of securing an army outpost there that had been surrounded by insurgents.

An official with the Kachin Independence Army confirmed Lajayang was quiet, but he said fighting was taking place in at least three other rebel positions in the region on Saturday. The official declined to be identified because he is not a spokesman for the rebel group.

Kachin Independence Army recruits in training.

Kachin Independence Army recruits in training. Photo: AP

The two sides have been fighting for 1 1/2 years, but the latest combat has represented a major escalation because the government began using fighter planes and helicopter gunships in its attacks starting on Christmas Day. Many of the skirmishes have centered on Lajayang, which is about 10 kilometers (6 miles) from Laiza, a town that also serves as a political headquarters for the guerrillas.

The upsurge in violence has drawn calls from the international community for the two sides to put down their arms and negotiate, but there was no public indication of any direct talks taking place.

Speaking at a development forum in the capital, Naypyitaw, President Thein Sein invited the Kachin rebels to an upcoming peace conference with 10 other armed ethnic groups, although no date has been set for the talks.

“I just want to stress that we continue to try to achieve genuine peace in the country,” Thein Sein said, adding that he had ordered the army and other government agencies to seek peaceful solution.

But the Kachin rebels, he said, “will need to reciprocate in a similar way.”

There was no immediate word on whether the Kachin would take up the president’s offer.

Tension with ethnic minorities fighting for greater autonomy in Burma is considered one of the biggest major long-term challenges for reformist Thein Sein, who inherited power in 2011 from the army, which ruled for almost half a century.

The Kachin, like Burma’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 Thein Sein’s administration.

A cease-fire that held for nearly two decades broke down in June 2011 after the Kachin refused to abandon a strategic base near a hydropower plant that is a joint venture with a Chinese company. The conflict has forced about 100,000 Kachin from their homes since then, and many are in camps near Laiza, where they have been digging bomb shelters and bunkers out of fear of air and artillery attacks.

The recent fighting flared after the Kachin rejected a government demand that they stop attacking convoys delivering supplies to the army base at Lajayang. The guerrillas contended that the convoys carried ammunition that could be used to attack their own nearby headquarters. The government then launched its offensive to clear the road to its base.

On Saturday, the Kachin rebel official said the latest fighting was taking place at Hka Pot and Hka Ya Bhum, both rebel-held hilltop posts located to the north and west of Laiza, respectively. He said fighting was also taking place in Hphakant, more than 160 kilometers (100 miles) further away.

He said the army had launched new assaults in each of the locations, but it was impossible to verify the claims.

Ye Htut, a presidential spokesman, denied the army was carrying out any new strikes, saying “we have completely stopped all offensives.”

But he said the military would retaliate if attacked and said the army has “reiterated its commitment to the president’s instruction to stop offensives except for self-defense.”

Ye Htut did not directly confirm whether there was fighting Saturday, but he accused rebels of attacking a police station in Hphakant before dawn, killing two police.

He also said about 20 civilians were injured when a convoy of three passenger buses struck what he said was a rebel landmine on a highway at Bamaw, several dozen kilometers (miles) west of Laiza.

Min Htay, a member of the All Burma Students Democratic Front, a dissident group that is fighting alongside some KIA units, also said the army was shelling a rebel outpost at Kka Ya Bhum with artillery on Saturday. Myanmar is also called Burma.

“The government announced last night that they will stop offensives,” Min Htay said, “But in practice, troops continue their barrage.”

Min Htay said hundreds of government ground forces overran three rebel hill posts around Lajayang in fierce battles on Friday, forcing outnumbered guerrillas to retreat.

Friday’s announcement that the army was ceasing offensives said that since December, 35 soldiers were killed and 190 wounded in Kachin state. The total number of Kachin casualties is not known, though the group’s supporters said it included civilians.

The government also said that since the war reignited in 2011, there have been 1,095 skirmishes with the guerrillas, who it also blamed for blasting 133 roads and bridges with explosives and laying land mines that wounded civilians at least 30 times.