President Thabo Mbeki on Wednesday called on South Africa’s military to help quell widening attacks against immigrants in the nation’s poorest neighborhoods, where images of riots, overwhelmed police and burning victims have revived chilling memories of apartheid-era violence.

At least 13,000 people have been chased from their homes, often a step ahead of mobs demanding that foreigners return to their native countries. News reports put the death toll at 42, with hundreds injured.

The attacks started in the Johannesburg township of Alexandra but have spread quickly. More than 400 people have been arrested, but it remains unclear who might have organized the initial attacks.

Police officials requested assistance from the military on Tuesday, said police spokeswoman Sally de Beer, and Mbeki approved the request Wednesday. She said troops will be deployed “as soon as possible.”

Stockholm, Sweden

Workers arrested in plot attempt

Swedish police arrested two maintenance workers on suspicion of plotting sabotage after they tried to enter a nuclear power plant Wednesday with traces of a powerful explosive like that used in the 2005 London transit bombings, officials said.

The plant’s operator, OKG, said no bomb was found and the incident did not pose a threat to the Oskarshamn generating station, which provides 10 percent of Sweden’s electricity.

Experts said a bagful of the suspected explosive would not be powerful enough to damage a nuclear reactor but could wreak havoc in a power plant’s control room.

The two men were contractors hired to do maintenance work on one of the facility’s three reactors, which was shut down May 11 for an annual check, plant spokesman Roger Bergman said.

Police did not release the men’s identities.

After questioning, both men were formally arrested on suspicion of preparing sabotage, a crime punishable by up to two years in prison, the Justice Ministry said.