YANGON: Myanmar troops attacked rebel positions in northeast Kachin on Sunday despite a ceasefire order from the president and an invitation to the rebels to take part in peace talks, a rebel spokesman and a local source said.

President Thein Sein issued the ceasefire order to troops in the La Ja Yang area of Kachin near the border with China, where fighting has been fiercest.

It was due to take effect on Saturday morning, but Colonel James Lum Dau, a Thai-based spokesman for the Kachin Independence Army (KIA), told Reuters the army had continued to attack over the weekend, both in La Ja Yang and elsewhere in the state.

An offensive in La Ja Yang from about 8 a.m. on Sunday morning (0130 GMT) had involved artillery and infantry, he said.

A 17-year ceasefire with the KIA broke down in June 2011 and fighting has been particularly intense in recent weeks.

Twenty months of fighting has displaced tens of thousands of people and, for some analysts, raised doubts about the sincerity of all the political and economic reforms pursued by Thein Sein in Myanmar, also known as Burma.

Addressing a development forum attended by donor countries and international aid organisations on Saturday, Thein Sein had invited the Kachin rebels to a "political dialogue" with rebels from other states.

Ten other major rebel groups from various states have already agreed to a ceasefire.

A local source in Kachin, who did not want to be identified, confirmed the army attacks on Sunday, including one on a rebel position about five miles (eight km) from the KIA stronghold of Laiza.

Fighter jets had flown over the area but had not attacked, the source said.

New York-based Human Rights Watch last week accused the army of indiscriminately shelling the town of Laiza.

Loud explosions were also heard by residents of the town of Mai Ja Yang who felt the vibrations, the source said.

MORE GOODWILL NEEDED

Colonel Lum Dau said the KIA had sent the president a reply saying it would not attend talks until there was more evidence of goodwill on the government side, involving a ceasefire in the whole state, or at least a big reduction in fighting.

"We already agreed to a ceasefire in 1994 and look at where we are now ... We didn't break any agreement," he said, expressing KIA mistrust of central government that has persisted even after Thein Sein took office in 2011 at the head of a quasi-civilian government after half a century of military rule.

A statement from the Kachin Independence Organisation, the political wing of the KIA, said "the government should reduce offensive operations all over Kachin State instead of suspending operations in La Ja Yang region". Further clarification of its demands was not immediately available.

Lum Dau said the government was simply buying time and would use any ceasefire to put troops in place for another assault on rebel positions.

He argued that it had only agreed to the partial ceasefire in response to diplomatic pressure from the United States and others, including China, which called for a halt to fighting on Jan. 15 after a shell landed on its side of the border.

There was no immediate response from the government to the rebel accusations of continued attacks in La Ja Yang, but it said rebels were responsible for attacks elsewhere in Kachin at the weekend.

Presidential spokesman Ye Htut said rebels attacked Kamine police station in the Phakant area in the early hours of Saturday, killing two policemen, wounding five and setting the building on fire.

He also blamed rebels for setting off mines that wounded about 20 people travelling in cars on the road from Bamaw to Lwejei on Saturday.