The U.N. war crimes tribunal convicted five Bosnian Croats today for a massacre of Muslim civilians in Bosnia in 1993 and sentenced them to a total of 64 years in prison.

Judge Antonio Cassese of the International Criminal Tribunal for the Former Yugoslavia in The Hague, rendered guilty verdicts to the five on charges of crimes against humanity for the rampage on April 16, 1993, when more than 100 Muslim civilians, including 33 women and children, were slaughtered under their supervision.

The central Bosnian village of Ahmici where they died, the judge said, "must be added to the long list of previously unknown hamlets and towns that recall abhorrent misdeeds and make all of us shudder with horror and shame." He cited other names on the list: Dachau, Germany; the Katyn forest in Belarus; Soweto, South Africa; My Lai, Vietnam; and Sabra and Shatila in Lebanon.

Vladimir Santic, who headed a Bosnian Croat militia in the area known as the Jokers, got the toughest sentence: 25 years in the tribunal's penitentiary outside The Hague. Drago Josipovic, one of his lieutenants, drew 15 years.

The case was sometimes called the Kupreskic case because three other defendants bore that surname. Brothers Zoran and Mirjan Kupreskic were sentenced to 10 years and eight years respectively, and their cousin Vlatko Kupreskic received a six-year sentence. The three Bosnian Croats carried out the machine-gun killings and house- and mosque-burnings that day.

A sixth defendant, Dragan Papic, was acquitted for lack of evidence and released from detention. All but Vlatko Kupreskic, who was arrested by NATO forces, surrendered to the tribunal more than two years ago. The defendants and their lawyers and guards were present in the courtroom, news agencies reported, and the lawyers said they would appeal the decisions.

The convictions were a milestone in the tribunal's seven-year history. The 15-month trial, the largest handled by the tribunal to date, heard testimony from 158 witnesses. The full judgment is 340 pages long.