CHIANG MAI, Thailand -- The rebel Shan State Army (SSA) has withdrawn from border outposts captured from Myanmar troops near the Thai-Myanmar border a month ago, rebel sources said Friday.

"The SSA have withdrawn its fighters from all mountainous positions near the Thai border captured last month to avoid direct confrontation with ethnic groups," SSA spokeswoman Nang Khur Hsen told AFP.

She said that Myanmar's ruling military regime had ordered minority groups who have signed cease-fire agreements with Yangon to fight against the SSA.

"Our enemy is the SPDC (State Peace and Development Council). We do not want to kill minority people as they are our brothers," SSA said.

The SPDC is the official name of Myanmar's ruling military regime.

"Since the fighting began, we have said that we would eventually withdraw and that we did not intend to permanently hold onto the bases," she said, adding that the SSA wanted to destroy camps harboring amphetamine and heroin production facilities.

Thai villagers living along the Myanmar border told AFP that the Myanmar troops had yet to reclaim the bases.

"They are continuing shelling on mountain positions that were left empty by the Shans 12 hours ago," a village source said.

Several hundred of the junta's troops died or were wounded during the offensive they launched on May 20 to recapture border outposts that were overrun by the rebels, the SSA spokeswoman said.

Fourteen SSA fighters had been killed and 25 injured, she said.

However, a Thai military observer estimated on June 9 that up to 100 Myanmar troops had by that stage been killed during fighting, while some 50 Shan fighters had been killed or injured.

Meanwhile, Myanmar denied a report in the Thai Press Friday that Thai troops were searching for physical evidence that Myanmar troops had been using chemical weapons against the SSA.

"It is regretful that such routine, deliberate and ridiculous allegations made by such terrorist groups are given much attention and highlighted by the Thai media to create more harm to the bilateral relationship between Myanmar and Thailand," a junta spokesman said in a statement.

The border clashes have prompted a serious deterioration in bilateral relations between the two countries, with Myanmar accusing Thailand of providing military support to the SSA.

Thailand refutes the claim.

The SSA is one of the few major armed insurgent groups in Myanmar yet to sign a cease-fire agreement with the ruling junta.