But he still maintained that the 78-day air campaign had been a success.

"We destroyed, we struck enough. The conflict ended on Nato terms," Gen Clark said.

Lower figures

During the air campaign, Nato said its planes had hit hundreds of Yugoslav tanks and other military vehicles.

General Wesley Clark: "We destroyed enough... we succeeded"

The Yugoslav army said that only 13 tanks were destroyed, a figure that was widely reported in the media at the time.

And when foreign journalists were able to go into Kosovo, they found little evidence of damaged Yugoslav armour.

The BBC's Mark Laity; "The debate over the true impact of Nato's air campaign will continue"

The newly-released figures say that Nato planes hit 93 tanks - not 110 as was stated at the time. The number of armoured personnel carriers hit was 153 - not 250. And a total 389 artillery and mortar pieces were struck, rather than the initial estimate of 450.

The details were given during a report on a Nato investigation into the air campaign, which ended on 10 June and paved the way for K-For to enter Kosovo.

Gen Clark's report says that Nato bombs had a good success rate

The figures were revised downwards after it appeared that some of the targets Nato thought had been hit were in fact the same targets hit several times, or decoys planted by the Serb forces.

Gen Clark flatly denied suggestions that Nato had lied about its effectiveness during the war, pointing to the stacks of strike report files and emphasising: "We have confidence in these results."

Tanks removed

In an assessment of the campaign, Gen Clark acknowledged that only 26 tank wreckages - "physically documented catastrophic kills," in the evaluation jargon - had been found on the ground by inspection teams, but said the Serbs had removed the rest.

BBC Defence correspondent Jonathan Marcus: Just how well did Nato aircraft perform?

"It is just basic military doctrine to clean up the battlefield after an engagement," US General John Corley, head of the assessment team, told a press briefing backed by slides, graphs and cockpit videos.

"There was extensive evidence that the Serbs quickly removed their damaged equipment from the battlefield," said Gen Corley, displaying footage of what he said were bomb-damaged Serb tanks and mobile artillery being hauled north out of Kosovo.

Investigators went back exhaustively over cockpit videos, pilot debriefings and aerial surveillance, as well as evidence later collected by teams on the ground.

Some parts of Gen Clark's report will remain secret

In nine cases, the tanks hit were plastic decoys. But Nato says such attacks were not a mistake.

"We intentionally destroyed decoys to prevent the Serbs from using them as ambush traps," Gen Corley said.

In other cases, questionable evidence ruled out claiming hits although pilots had confidently reported them.

A section of Gen Clark's report which is to remain classified deals with Nato's own deficiencies in the air campaign and the subsequent deployment of peacekeeping troops to Kosovo - and the lessons which should be drawn from them.

The BBC's defence correspondent Jonathan Marcus says most experts now believe that, while the attacks in Kosovo itself were necessary, the real damage to the Yugoslav leadership's will to fight was caused by the attacks on fixed targets in Serbia proper.