PARIS, May 26 (AFP) - Here is a summary of Kosovo-related developments over the past 24 hours: -- NATO agreed to boost the number of troops in a future Kosovo peacekeeping mission from 28,000 to 45,000, reviving speculation that the alliance was eyeing a ground offensive. Before NATO's bombing campaign against Yugoslavia began on March 24, the 19-member alliance estimated it would only need about 28,000 troops for the force. -- EU, Russian and US envoys on Wednesday launched a fresh effort to hammer out joint proposals to end the Kosovo crisis that could be submitted to Belgrade, amid caution about any breakthrough. US Deputy Secretary of State Strobe Talbott called the Kosovo crisis "a very difficult matter" but vowed that negotiations would press ahead, after meeting with Russian Foreign Minister Igor Ivanov. -- British Foreign Secretary Robin Cook was due in Bonn Wednesday for talks with German Foreign Minister Joschka Fischer on the Kosovo crisis. The two ministers represent divergent points of view within NATO, with Britain calling for a ground invasion of Kosovo if necessary while Germany says it would oppose this. Cook was to arrive here from Italy where he met opposite number Lamberto Dini and was to leave later for France, where he will talk with French Foreign Minister Hubert Vedrine. -- NATO said Wednesday it had struck a villa belonging to President Slobodan Milosevic for the second night running as the allies conducted their heaviest raids yet against Yugoslavia. Warplanes flew a total of 650 sorties, 284 of them strike sorties and 74 intended to take out Serb anti-air defences. The number of sorties was the highest recorded since the bombing campaign began on March 24. -- NATO denied that one of its Harrier attack aircraft was shot down overnight by Yugoslav anti-aircraft fire. "All planes returned to base without problems," a NATO communique said, denying a report by Tanjug news agency. -- An estimated 965,975 ethnic Albanians have fled Kosovo since the start of the crisis nearly 15 months ago, according to figures released by the UN High Commissioner for Refugees (UNHCR). Around 778,400 of these left Kosovo after the start of NATO air strikes against Yugoslavia on March 24 and are in Albania, Bosnia, Macedonia and Montenegro, the UNHCR said. -- Tensions surfaced in Montenegro's government over how much the little republic should stand up for itself against its Yugoslav partner, the more powerful Serbia dominated by Slobodan Milosevic. Differences within the Montenegro coalition surfaced over a document Montenegro will present to a session of the European Union on Balkans stability in Bonn on Thursday. -- Two Australians and a Yugoslav working for the charity CARE International went on trial in camera in a military court in Belgrade, charged with spying. Steve Pratt and Peter Wallace, detained by Serbian authorities at the border between Serbia and Croatia on March 31, were charged earlier this month with spying for NATO, along with a Yugoslav national, Branko Jelen. They face between 10 and 20 years' imprisonment under article 128 of Yugoslavia's penal code.  