THE HAGUE, Netherlands?In a blow to prosecutors, the Yugoslav war crimes tribunal overturned the convictions Tuesday of three Bosnian Croats sentenced in one of the worst massacres of the Bosnian war.

Calling the trial ?critically flawed,? the panel ordered the three defendants immediately released and reduced the sentences for two others.

The five were convicted in January 2000 of participating in the 1993 massacres in Ahmici, where more than 100 Muslim civilians, including dozens of women and children, were killed.

It was the first time since the court was created in 1993 that an appeals chamber of the U.N. tribunal threw out the convictions of a lower court and acquitted the defendants.

Within hours of the ruling, two brothers and their cousin were hustled from the U.N. detention center, where they had been held for four years.