The latest Yugoslav news agency figures say 81 civilians were killed in Thursday's overnight bombing of the village of Korisa.

US Pentagon Spokesman Ken Bacon said the Serbs "had to have known" the building which the Kosovo Albanians slept next to was a military target because Nato had hit many similar installations over the last seven weeks.

BBC World Affairs Correspondent Kevin Connolly: "A lot of questions unanswered"

"It certainly looks like this was arranged to make them human shields but we cannot confirm this," he said.

Yugoslav Foreign Ministry spokesman Milisav Paic has dismissed this suggestion as "crazy".

"There is no doubt it was Nato who carried out the raids against civilians and they cannot just simply try to get rid of any responsibility," he told the BBC.

At a briefing on Saturday, Nato said it had dropped 10 bombs on Korisa, saying it was a "legitimate military target".

It said the village was being used as a military camp and command centre and "deeply regretted" any accidental civilian casualties.

Jacky Rowland: "Our ability to investigate is quite limited"

BBC Correspondent Jacky Rowland, who visited the village on Saturday, said she saw no evidence of any military equipment in the area although if there had been any it could have been moved over the past 24 hours.

The Yugoslav government has sent a letter to United Nations Secretary General Kofi Annan saying the latest attack was a "striking example of the Nato aggression's genocidal character".

There has been further criticism of Nato's bombing campaign from United Nations Human Rights Commissioner Mary Robinson. She told Irish radio the offensive had lost its "moral purpose".

Military analysts say accidents involving civilian casualties are made more likely because of Nato's tactics of bombing from high altitude.

UNHCR fights back

Nato Spokesman Jamie Shea: "We attacked a legitimate military target"

Meanwhile, the United Nations refugee agency (UNHCR) has attacked a report by UK MPs which accused it of coping badly with the Kosovo refugee crisis.

The UNHCR says it was not consulted by the MPs on the Commons select committee and say the criticism was "regrettable", and in some cases based on inaccurate information.

UNHCR spokeswoman Judith Kumin said observers visit the camps for 24 hours, getting only a "snapshot" view.

"It would be much better to see them working day after day, week after week and month after month in exhuasting conditions," she said.

And the UN team heading for Kosovo, has left Geneva for the first part of its humanitarian mission to Yugoslavia.

Sixteen people from the UN's main agencies as well as the British Save the Children Fund, are on the way to Zagreb, from where they will travel overland to Belgrade.

The team expects to be in Belgrade on Sunday and in Kosovo by the middle of next week.

Mission spokesman, David Chikraidze, said the team, which would be escorted by Yugoslav police, had been assured access to some of the towns where refugees had spoken of systematic ethnic cleansing.

The questions over responsibility for the deaths at Korisa did not deter the Nato alliance from further bombing overnight.

(Click here to see a map of the most recent Nato strikes)

According to the official news agency, Tanjug, many bombs and missiles fell in the triangle formed by three large towns in central Serbia - Kraljevo, Klagujavac and Cacak.

Embassy fall-out clears

The diplomatic fall-out from the Nato bombing of China's embassy in Belgrade appears to be easing.

After repeated US apologies Chinese President Jiang Zemin and US President Bill Clinton held their first telephone conversation since last Friday's attack which Nato said was a result of using outdated maps.

The UN Security Council has also expressed "profound regret and deep sorrow" for the attack, after a week of bitter wrangling in which China's proposed text was diluted.

• Picture gallery: Village 'bombing'
• UNHCR hits back at critics
• UN 'regrets' embassy attack
• Nato dumps bombs in Adriatic
• Montenegrin president condemns Milosevic

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