Subir Bhaumik in Moreh on the India-Burma border

Indian officials say Burma has released all the separatist militants from the north-east Indian state of Manipur, who were arrested during a Burmese military operation along the India-Burma border last year.

Sources in the Burmese border police say the last batch was let out last week.

Armed militancy is rife on the borders

Officials of the Indian Border Security Force (BSF) say that Burma turned down their request to hand over the Manipuri rebels to India.

In early November last year, Burmese security forces launched a major offensive against the Manipuri rebel bases around Tamu, the Burmese town just opposite Moreh.

Nearly 200 rebels of three Manipuri separatist groups active in India and based just across the border in Burma were arrested.

More than 1,600 weapons were seized, along with substantial quantities of gold and cash in various currencies.

Those arrested included RK Meghen, chief of the United National Liberation Front; Jibon Singh, the military commander of the Peoples' Liberation Army, and four other senior rebel leaders.

Non-cooperation

The BSF says it made an immediate request to their Burmese counterparts for handing the rebels over to Indian authorities.

When Burma refused, India requested detailed information on the arrested rebels and their leaders.

Manipur is a high-security region

The BSF's Manipur area commander BK Mishra told the BBC that the Burmese stopped cooperating after initially agreeing to do so.

Instead, he said, the rebels were set free in batches this year.

Sources in the Burmese border police in Tamu talked to the BBC on conditions of anonymity.

They said the last batch of 27 Manipuri rebels was set free from a prison in the western Burmese town of Kalemyo last week.

They said the rebels had now disappeared into the thick jungles of Burma's Sagaing division.

It is not clear why Burma's military rulers, who started the offensive against the Indian rebels in their territory last year, decided to release them.

This release will surely upset India.

Earlier last year, following reciprocal visits by their military commanders, the two countries had agreed to coordinate military activities against separatist groups active along the border.