According to United Nations and Bosnian Serb military sources, members of elite Yugoslav Army units have been fighting in Bosnia on and off for the past year, and are involved in an important operation near Tuzla.
The sources say Yugoslav paratroopers are the spearhead of a Serbian plan to isolate Tuzla, a UN-declared 'safe area' of almost 400,000 people and the largest remaining multi-ethnic city in Bosnia with a viable industrial base.
Nato last week threatened air strikes unless the Serbs allow Tuzla airport to open for international aid flights. But the Bosnian Serb leadership has refused to comply until after a peace deal is signed.
Peace talks between the Bosnian factions resume tomorrow in Geneva, amid scant hopes of a settlement. Muslim leaders say talks would be a useless charade unless Serbs return land belonging to Muslims.
Nato sources said the alliance would study plans to bomb Serbian positions round Tuzla and Srebrenica this week. A spokesman said the alliance would lose credibility if it failed to carry out such threats in the face of continuing Serbian defiance.
But the outgoing commander of UN forces in Bosnia, General Francis Briquemont, said threats of air strikes to break Serbian sieges were unrealistic. 'You can't break siege cordons around cities like Srebrenica, Gorazde or Mostar with air attacks.'
Milos Basic, a respected military correspondent on the liberal Belgrade newspaper Vreme, said the Yugoslav Army high command has sent troops in because the Bosnian Serb army is inefficient. The implication was that if the Bosnian Serbs could take care of themselves, Belgrade would not have to help them.
Weapons flow in, page 10
Leading article, page 15Reuse content