Serbian military to allow air-drops: As the US prepares to go it alone on aid, Nato foreign ministers find there are gaps emerging in the transatlantic alliance

LEAFLETS could be dropped as soon as this weekend on Muslim enclaves in eastern Bosnia, warning locals to get out of the way of falling food parcels. There are signs that Bosnian Serbs do not intend to disrupt the air-drop operation.

The leaflets, written in both Roman and Cyrillic scripts, will pave the way for the air-drop of desperately needed aid to up to 100,000 Muslims in the region, who are trapped in half a dozen towns and villages that are holding out against Bosnian Serbs.

Awacs aircraft from bases in Hungary and the Adriatic are to monitor the skies over Bosnia during the operation, following a meeting yesterday of Nato foreign ministers in Brussels with the US Secretary of State, Warren Christopher.

The air-drop operation is mostly symbolic, as the amount of aid will be small. The average cargo of the C-130 Hercules planes will weigh 80 tons. Each plane will carry 16 bundles of food and medicine, including flour, cooking oil, rice, coffee beans and pre-packaged meals.

Officials from the United Nations High Commissioner for Refugees (UNHCR) will inspect each plane before take-off to ensure weapons are not included in the air-drop. In Geneva, a UNHCR spokeswoman described the operation as 'an extension of the airlift to Sarajevo'. The principal difference is that the planes will not land.

Earlier fears that the US initiative might exacerbate the fighting and spark off retaliatory attacks by Bosnian Serb fighters against the 7,500 UN peace- keepers in Bosnia have receded. The US has backed off from plans for combat jets to accompany the aid planes and say the food parcels will be dropped on Croat- and Serb-held areas of Bosnia, as well as on besieged Muslim enclaves.

The planes are to fly in groups of three, at a height of 6,000ft to 10,000ft and mostly at night, to reduce the likelihood of being hit by Serbian or Bosnian army anti-aircraft fire.

These modifications to the plan, and placing the operation under UN auspices, have allayed some suspicions on the Serbian side that the operation is a first step towards US intervention on the side of the Muslim-dominated Bosnian government. Earlier this week the Yugoslav army condemned the air-drop plan as 'an imperial diktat', and warned they would 'take steps' to prevent possible territorial aggression - presumably by the US - against the rump Yugoslavia.

But Bosnian Serb military chiefs have taken a more conciliatory stance. In a statement to the Serbian news agency Tanjug, Bosnian Serb military commanders ordered their units not to fire on humanitarian aid planes or disrupt the operation in any way. 'The Bosnian Serb army has a very co-operative relationship with humanitarian aid and has never stooped its passage,' the statement added. 'All the humanitarian help given to the Muslim side so far has passed through Serbian territory.'

In Belgrade, the Serbian government of Slobodan Milosevic has adopted a neutral stance towards the air-drop plan, in keeping with official claims that the rump Yugoslavia, consisting only of Serbia and Montenegro, is not involved in the Bosnian conflict. Despite blessings from all warring sides, UN officials still fear rogue Serbian or Bosnian army commanders will fire on aid planes - the Serbs to stop food from reaching their Muslim enemies, the Muslims in order to cast blame on the Serbs and heighten the chances of US military intervention in the conflict.

Another fear is that bundles weighing several tons and dropped from a great height could land on people and kill them, or miss their target zone entirely. The Bosnian Serb leader, Radovan Karadzic, has predicted that the wind will blow food bundles destined for Muslim enclaves into Serb-held regions.