One African youth was killed and another injured today as South Africa braced for observances Thursday of the first anniversary of racial unrest in black townships.

Eyewitnesses here in Johannesburg's black African ghetto saod 17-year-old Philemon Tlowana was beaten to death by camouflage-clad police after a store was stoned and looted by a group of angry youths. Tlowana allegedly was caught after running from the shop. Police told reporters at the scene, "Stay away. It's none of your business."

A second youth received minor shotgun wounds when police fired warning shots at a group of students in Meadowlands sub-township, according to reporters on The World, South Africa's black newspaper.

Although a two-day boycott of classes and work, called by the Soweto Students' Representative Council, is not scheduled to begin until Thursday, there have been isolated incidents for the past week as the anniversary approached. Tension mounted today as armored cars, vans and police cars began heavy patrols. Roadblocks were set up at all entrances to the sprawling township of more than a million black Africans, and police searched cars and demanded identity papers.

There were several indidents of rock-throwing at passing vehicles, in addition to the looting of the store. Most students apparently boycotted classes, although hundreds were seen milling around schoolgrounds, often jeering at police and cars carrying whites.

At Morris Isaacson High School, students warned a group of white reporters they would "face great daners" if they remained near school yards. "They are so angry anything could happen. Please go, for your own sakes," one black youth said.

On streets near three high schools, police fired tear gas to disperse students gathered in small groups. Near Orlando High School a patrol car sped down a dusty side street with police firing tear gas as they encountered youths. South African-designed "Hippo" armored cars were stationed at key points around the 26-square-mile township.

Although the major events scheduled for Thursday's commemoration are church services, many observers fear that trouble could erupt from the nervousness of police and students.

Feelings have been heightened on boths sides. The police are tense in the wake of an attack by three blacks on a group of whites in Johannesburg Monday, killing two, and an explosion that blew up a section of railay near Durban today. Black youths $99;LINE ILLEGIBLE£ dentention of at [LINE ILLEGIBLE] over the week [LINE ILLEGIBLE] police.