Many high school students boycotted classes here yesterday following distribution of leaflets Thursday urging a "day of mourning" for the "massacre" last week at the University of Liberia, academic sources told Reuter.

The sources said more than 60 percent of students in some schools had stayed away to protest events last week when Liberian leader Samuel K. Doe ordered troops to disperse demonstrating students. The students were protesting the arrest of a university professor whom Doe has accused of plotting to overthrow him.

A call in the pamphlet, however, for private- and public-sector workers to strike apparently was not heeded, sources added.

Some students say about 20 demonstrators died and 17 others disappeared during the confrontation with the troops. A private New York-based Liberian Community Association has charged that government troops fired directly at demonstrators, killing 50 people and wounding 400.

Health Minister Martha Sandolo Belleh, in a press conference yesterday, gave a different version of the confrontation. Belleh said 102 people were hurt, including five by bullets, when troops dispersed the demonstrators. Earlier government reports said only three were injured, all by stray bullets.

In a separate briefing for reporters, Defense Minister Gray Allison said that Liberian saboteurs trained in Ethiopia, Cuba and other Marxist countries were responsible for the student protest against the arrest of Prof. Amos Sawyer.