NATO is stepping up its aerial assault on Yugoslavia, with no Easter break, in a desperate attempt to make up time lost, partly through bad weather, after Serb forces were reported to be continuing their attacks on ethnic Albanians in Kosovo.
The US has reinforced its strike force with 12 more F-117A stealth bombers and five B1 bombers of the cold war era stationed at Fairford in Gloucestershire. Other NATO countries were said to be ready to commit aircraft to add to the 400 already based at Italian airfields.
B1 bombers, in action for the first time in the Kosovo conflict, attacked Yugoslav lines of communications, including bridges, according to NATO officials.
With the refugee crisis worsening, NATO governments are under increasing pressure to show that the air bombardment is having results on the ground. Poor weather on Thursday night again forced aircraft - including RAF Harriers, which have so far attacked just two targets - to abort their bombing missions.
Despite official denials in London and Washington, NATO planners are considering putting in a ground force. Gen Wesley Clark, the NATO Supreme Commander, said on Thursday that he would not "discuss any details or a time line on what such a mission might be". He acknowledged, however, that "air power alone cannot stop paramilitary murder".
British officials said yesterday there were no plans "at the moment" to send in a NATO ground force and President Clinton, in a speech in Norfolk, Virginia, on Thursday called for patience. The US administration remains officially confident that its air strike strategy will accomplish NATO's war aims. Mr Clinton, guided by his private opinion polls, is as usual ready to launch air and missile attacks, but reluctant to go further.
Meanwhile, Serbia said yesterday it had begun collecting evidence for criminal proceedings against three US soldiers seized by the Yugoslav army.
The news came despite what appeared to be a strong warning from President Clinton that the three should be returned to the United States and not put on trial.
"There was absolutely no basis for them to be taken," Mr Clinton told several thousand military personnel and their families gathered in an aircraft hangar in Norfolk, Virginia. "There is no basis for them to be held. There is certainly no basis for them to be tried," he said.
It was not clear where the servicemen were being held or whether they had appeared in court or given any statement.
"The process of collecting evidence, on the basis of which a criminal procedure starts, is under way. More details will be available on Saturday," said a Serbian official in Kosovo, contacted by telephone.
On Thursday, Yugoslavia's Tanjug news agency quoted a Serbian official as saying criminal proceedings would start yesterday before a competent military court.
NATO has said that the three - Mr Christopher Stone (25), Mr Steven Gonzales (21) and Mr Andrew Ramirez (24) were seized on Wednesday while patrolling the Yugoslav-Macedonian border. Yugoslav authorities have said they were captured on Yugoslav territory.
Tanjug said yesterday they were on a reconnaissance mission and crossed into Yugoslav territory from neighbouring Macedonia. The three were shown on Serbian state television on Thursday, bearing signs of bruising.
Yugoslav and Serbian authorities have provided no information as to what charges the three men might face.
In an interview, the US Defence Secretary, Mr William Cohen, said a Yugoslav military tribunal would be "a kangaroo court". ". . . There should be no trial," he said.
But Mr Strahinja Kastratovic, a prominent Belgrade lawyer, took a different view. "We have a state of war declared here and these soldiers are prisoners of war," he said. He said the three were captured "in the uniforms of an aggressor country, on a territory their aggression made an enemy territory, and they must stand trial".
The charges could include spying and terrorism and sentences could vary from up to 20 years of imprisonment to the death penalty, he said.
"The same thing would have happened if US army captured Yugoslav soldiers on their own territory or territory they control," Mr Kastratovic said.
"If they bomb they have to face the consequences of the situation they created".
NATO kept up its air attacks on Yugoslavia yesterday and made plans to increase the effort while friends and family of two of the soldiers hung yellow ribbons in their hometowns in Texas and Michigan in a symbol of support for them.
"[Yugoslav] President [Slobodan] Milosevic should make no mistake; the United States takes care of its own," Mr Clinton said yesterday. Also yesterday, Tanjug said two Yugoslav citizens were charged, one with espionage for the United States and the other for illegal entry into a military premises.
