Arrests Made in S. Africa Racial Attacks : Violence: Nine whites held in murders outside Johannesburg. A fifth black is charged in fatal assault on Cape Town bar.

Police announced breakthroughs Friday in two recent racial attacks, arresting nine white men accused of murdering and mutilating blacks and arresting a fifth black militant allegedly involved in a brutal assault on a mostly white Cape Town bar.

Although more than 13,000 people have been killed in political violence since the government began dismantling apartheid four years ago, terrorist attacks by paramilitary groups clearly motivated by racial hatred are rare.

The two attacks last month sent waves of rage and fear across this nervous nation, especially since the bloodletting is expected to grow as the country braces for its first democratic elections next April.

In Cape Town, police said they had arrested a fifth member of the Pan Africanist Congress, a radical black nationalist group that refuses to renounce its armed struggle against the white-ruled government. The group’s guerrilla wing has claimed responsibility for the bloody Dec. 30 attack on the Heidelburg bar.

PAC leaders denied involvement, however, and denounced the five arrests as “pure political gangsterism” designed to “rig the elections long before they start.”

Opening fire without warning, five black gunmen sprayed the crowded student pub with assault rifles, tossed a nail-studded grenade that did not explode and left three women and one man dead. Five others were wounded, including a university student who may be paralyzed.

Lt. Col. Raymond Dowd, a police spokesman, said investigators had also dug up a buried cache of weapons Friday, including four grenades with nails glued to them to increase their lethality, a 9-millimeter pistol and ammunition for R-4 assault rifles.

He said forensic and ballistic tests will be conducted to determine whether the cache is linked to the Heidelburg pub shooting.

Law and Order Minister Hernus Kriel said Wednesday that ballistics tests on some of the 90 bullets fired into the bar had already proved a “direct link” between the assault rifles used in the massacre and those fired during a similar terrorist attack last July at Cape Town’s St. James Church.

Eleven worshipers in the church’s multiracial congregation were shot to death or killed from exploding nail-studded grenades, and more than 50 people were wounded.

The apparent progress into the Heidelburg bar shooting was overshadowed, however, after a 14-year-old black youth was shot in the back and killed and four others were wounded during a botched police raid on a PAC political meeting late Thursday in Cape Town’s Guguletu township, a PAC stronghold.

Dowd said police fired rubber bullets and birdshot after a chanting mob of angry youths pelted them with stones and tried to free nine young men who had been placed in a police vehicle. The nine were released after questioning.

But Patricia de Lille, a PAC leader, said heavily armed police had fired without provocation and set dogs on the crowd.

She insisted that police used live ammunition, not rubber bullets.

In a separate case in Johannesburg, police said they had arrested nine white men for allegedly forcing two cars filled with blacks off a rural road west of the city early on Dec. 13. Two men and an 11-year-old boy were shot to death, and four others were seriously wounded.

Two of the survivors were found inside a vehicle that had been set ablaze. Both had been stabbed, and their ears had been cut off.

The terrified survivors told police that the killers spoke Afrikaans and wore camouflage fatigues, except one man dressed in black. Black boots and uniforms are worn by the Iron Guard, a neo-Nazi unit that protects Eugene TerreBlanche, leader of the white supremacist Afrikaner Resistance Movement.

TerreBlanche denied involvement.