The military chief in Indonesian West Timor has promised that members of an opposition group in neighbouring East Timor, an independent state, will be barred from crossing the border into West Timor.

Colonel M. Musanip, quoted Thursday by the state Antara news agency, said the military would not allow members of the "Kolimau 2000" group to enter West Timor where many former East Timorese refugees still live.

"If members of Kolimau 2000 opposition group enter our territory and then ask ex-Timorese residents living in camps to carry out a rebellious movement in East Timor, we will take stern action against them," Musanip said.

"There will be no leniency for them." News reports have said the leader of Kolimau 2000, indentified as Bruno, had entered West Timor to ask former East Timorese militiamen to help them create chaos in East Timor after the withdrawal of United Nations troops this May.

East Timorese officials have said Kolimau 2000 was apparently led by disgruntled former resistance fighters, disillusioned by a lack of jobs.

Indonesia invaded East Timor in 1975 and ruled it for 24 years. The Indonesian military in 1999 supported the formation of pro-Jakarta militias, who waged a bloody but futile campaign to thwart a vote by East Timorese in August that year to break away from Indonesia.

West Timor is still home to thousands of militiamen who fled the arrival of foreign peacekeeping troops in September 1999. Tens of thousands of other East Timorese who were forcibly moved across the border by militias at the time have now returned home.

East Timor became independent in May 2002 after a period of UN stewardship and the two countries have vowed to improve relations.