Police broke up protests by angry Kosovan Serbs in Belgrade yesterday as Serbia's umbrella opposition group demanded early elections and democratic change.
The British Prime Minister, Mr Blair, challenged the population of Serbia to oust President Slobodan Milosevic, saying they could no longer turn a blind eye to their country's atrocities in Kosovo.
NATO, fresh from clinching a deal to disarm ethnic Albanian guerrillas, vowed to stamp out ethnic violence in Kosovo and urged Serb refugees to return.
Two Nepalese Gurkha soldiers of the British army, and two civilians, were killed by a mine during an operation to clear explosives from a school, the BBC said.
As Western states contemplated the huge task of rebuilding the Balkans, President Clinton said Yugoslavia could be given help with emergency power supplies to stop people freezing this winter. But he ruled out repairing damage to the infrastructure, such as bombed bridges.
NATO and UN officials, anxious to stem the flow of Kosovan refugees risking a return home under their own steam, unveiled plans for organised repatriations in the next week or so.
NATO said it would start taking refugees home from Albania from July 1st onwards. The UN refugee agency, UNHCR, said organised journeys from Macedonia could begin sooner.
NATO said 2,000 Serbs had returned to Kosovo in the past 48 hours, days after fleeing to escape feared reprisals by returning ethnic Albanian refugees. Others are refusing to return.
Police broke up a second day of protests in central Belgrade by about 200 Kosovan Serbs and detained their leader, witnesses said.
"We're here to protest against the whole situation," said a Serb man from the Kosovan town of Prizren. "The government has manipulated us and left us without anything. They made us leave Kosovo and we don't have any assistance here - they just keep pushing us from one site to another.
"It's a madhouse down there right now. We would be killed or slaughtered if we go there. There's no security without the army, without police. You can't face them [ethnic Albanians] with your bare hands."
The government is pushing to get some 50,000 Serbs who fled Kosovo over the past week back into the region, promising police escorts, food, water and fuel for the journey home.
Under an agreement signed with NATO in the early hours of yesterday, the ethnic Albanian Kosovo Liberation Army (KLA) pledged to disarm partially and to refrain from carrying out reprisals against ethnic Serbs.
The accord says the KLA must follow a strict 90-day timetable for placing heavy weapons in storage depots, dismantling roadblocks and stopping its fighters from appearing in public in military uniform.
A relieved President Clinton telephoned the KLA commander, Mr Hashim Thaqi, from Germany to thank him for signing the agreement, which he described as an important step forward.
Mr Thaqi, speaking on his return to Pristina, held out an olive branch to his main ethnic Albanian rival, moderate leader Mr Ibrahim Rugova.
"There is room enough in Kosovo for him and he can help a lot in the political process here," Mr Thaqi told a news conference.
For the first time, Mr Clinton suggested that emergency aid to Yugoslavia could include help in restoring power supplies to, for example, keep hospitals running.
But he ruled out rebuilding bridges which NATO destroyed during its 11-week bombing campaign, to force an end to what the West called Serbian repression of ethnic Albanians in Kosovo.
"I don't buy that. That's part of their economic reconstruction and I don't think we should pay it, not a bit, not a penny," he said after meeting the German Chancellor, Mr Gerhard Schroder, and the European Commission President, Mr Jacques Santer.
Serbia's opposition umbrella group, the Alliance for Change, announced it would start organising demonstrations across the republic calling for early elections and democratic change.
"This is the last minute to reverse the present political course in Serbia and to demand the responsibility of those who have had unlimited power in the decision-making process over the last 10 years," said an Alliance official, Mr Milan Protic.
In Kosovo's capital, Pristina, NATO's British commander, Lieut-Gen Sir Mike Jackson, promised increased security to protect returning Serbs from attacks by ethnic Albanians.
Lieut-Gen Jackson apologised for several attacks on Serb homes on Sunday, the day the last Yugoslav troops withdrew from Kosovo.
"It should not have happened. We fell short of what we wanted," the general said.
European Union foreign ministers, meeting in Luxembourg, said they were "alarmed by the exodus of the Serb population from Kosovo", and urged all Serb residents of Kosovo to return to their homes.
Officials in Belgrade have been appealing to the Serbs' sense of identity with Kosovo, home of their church and site of a 14th-century battle which shaped Serbian history. If Serbs do not return, they say, there will be no Kosovo.