By Subir Bhaumik
BBC News, Calcutta
Troops in western Burma have captured a base used by separatists from neighbouring India after a week of fighting, a rebel spokesman has said.
He said that 12 rebel fighters from India's Nagaland state had been killed.
Burma shares a 4,000km (2,486-mile) border with north-eastern India. The region has been the centre of insurgent activity for more than three decades.
In recent times, Burma faced Indian pressure to push out the separatists from its eastern Sagaing Division.
The spokesman for the National Socialist Council of Nagaland (NSCN) said that Burmese troops had also suffered casualties, but could not specify how many.
Indian military intelligence says there is indeed some fighting across the border from Nagaland but could not provide details.
The bases of the NCSN's breakaway faction headed by Burmese-Naga leader, SS Khaplang, have been under attack from Burmese troops for about a week.
The NSCN is a divided organisation
But it was only on Thursday that the rebels first admitted to having lost a major base.
The spokesman of the NSCN's Khaplang faction, Kughalo Mulatonu, told the BBC that their base near the Naga village of Chuiyang Noknu had fallen to the Burmese troops.
He said at least 12 Naga guerrillas had been killed in a week of fighting before they had to retreat from Chuiyang Noknu.
Mr Mulatonu said two of their other bases in the same area were also being bombarded by mortars.
"We expect a Burmese infantry assault on those bases any time now," he said.
Mr Mulatonu said the Assamese separatists who were staying in their camps had already pulled out towards the border with India and had not got involved in the fighting.
Burma has faced huge Indian pressure in recent months to push out north-east Indian separatists from Sagaing Division.
Delhi has been providing Rangoon with substantial supplies of military hardware ever since Burma's military rulers promised to attack the separatists.