At a time when other Latin American governments have ignored or covered up activities of military-linked "death squads," the new government in Colombia has moved to prosecute members of such a group, the human rights group Americas Watch has reported.

In a report made public this month, Americas Watch praised Colombian President Belisario Betancur for his efforts to curb militarization in that country and specifically for the judicial process begun against a loosely organized terrorist group known as MAS, the Spanish initials for "Death to Kidnapers."

A report issued by Colombian Attorney General Carlos Jimenez Gomez in February named 163 alleged members of the group, including 59 military men, two of them colonels, on active duty. The Americas Watch report said local courts have begun investigating the attoney general's charges in order to put the accused on trial.

Americas Watch, with offices in New York and Washington, monitors human rights in the Western Hemisphere in much the same way that Helsinki Watch groups in Europe monitor compliance with the Helsinki accords on European security.

The human rights group's report said that MAS was considered responsible for 96 murders, 59 death threats and 46 cases of torture in 1982. Ironically, the group calling itself "Death to Kidnapers" had itself abducted 65 people, according to the report. The report added that the group's victims "rarely have included persons who could reasonably be suspected of authoring . . . kidnapings." Most of the victims, it said, were peasants, labor organizers, politicians, students and lawyers.

The report, written by consultant Cynthia Brown, said it was unlikely that the military men named in the attorney general's report would be tried by civilian courts.

It said high-level military officials had criticized the investigation and even "illegally ordered every soldier to set aside a day's pay for the defense of the 59 active-duty accused." The 59 are expected to be tried by military courts.

The decision to prosecute military officers for alleged involvement with death squads is unusual in Latin America, the report pointed out. In Argentina, where thousands of people were murdered or simply disappeared during the so-called "dirty war" against leftist guerrillas, the armed forces issued a statement in April absolving its members of responsibility. In El Salvador and Guatemala, military men accused of massacring civilians and other abuses have never been brought to trial.

The report also criticized the Reagan administration for a policy "which supports the military sector" in Colombia "while neglecting entirely the development or strengthening of civilian institutions."