A group of nearly 100 American Indians who have stood outside the U.S. Supreme Court building for almost two months said yesterday they plan to leave today, a day after the court refused to hear the appeal of American Indian militant Leonard Peltier.

A spokesman for the group, Roque Duenas, said his group sent a letter to the Congressional Black Caucus yesterday requesting that the Caucus investigate the incidents leading to the arrest and conviction of Peltier.

Peltier was sentenced in 1977 to two consecutive life terms for his conviction in the murders of two FBI agents on South Dakota's Pine Ridge Indian Reservation in June 1975.

Since his arrest and conviction, members of the American Indian Movement throughout the country have contended that Peltier shot the two FBI agents in self-defense. They also allege that the FBI fabricated information that led to the extradition of Peltier from Canada.

Here in Washington, while the Supreme Court was considering the case, members of the AIM have conducted at least one march throughout the downtown area and have maintained a vigil outside the court building.

Duenas, the Indian spokesman, said members of the group would continue their activities in their own communities until Peltier is free.