And there is, indeed, something else worrying residents and others, something even immigrant advocates hesitate to speak about. In 2010, the country was unnerved by rumors that more xenophobic violence would follow the final game of soccer’s World Cup, which South Africa was hosting. And there was some violence, though nothing like the rumors had suggested.

And now there are fresh rumors making the rounds in townships across the country that still more outbreaks of violence will be visited upon foreigners in the rush of emotions sure to follow the death of Nelson Mandela, the former president and anti-apartheid campaigner who has been hospitalized since June 8 and who turns 95 on Thursday.

“Yes, we are very concerned about that,” said Ayub Abdi, 19, an engineering student who works at his family’s shop in Mandela Park. “The customers know of this rumor, and they use it against you. If there is a dispute over some goods, they say to us, ‘Oh, you will get in a lot of trouble after Mandela dies.’ ”

Both Mr. Hanekom and William Kerfoot, a lawyer for the Legal Resource Center in Cape Town, which offers free counsel to immigrants and refugees, said that they and other advocates suspected that the rumors were baseless — “I certainly hope so,” Mr. Kerfoot said — though they might inadvertently stir trouble by providing a pretext for those needing little reason to loot.

“On the one hand, you don’t want to perpetuate the rumor,” Mr. Hanekom said. “On the other hand, you don’t want to ignore it because it has serious repercussions.”

Beverly Tsambi, 41, was in Mr. Abdi’s Mandela Park shop with her two grandchildren, looking over packets of chips.