South African police have opened a murder investigation after a foreign national was allegedly beaten to death by a crowd of about 50 people in Durban on Thursday morning.

The victim, believed to be in his late 30s or early 40s, was declared dead at the scene, the South African Police Service (SAPS) said in a statement.

According to preliminary police information, a group of people were marching along Dr. Pixley Kaseme Street toward Maud Mfusi Street in Durban's city center when two men broke away and approached the victim, who was standing by the roadside. The crowd then allegedly attacked him.

Police said the motive for the killing had not been established and investigators were following several leads to identify those involved.

The killing comes amid heightened tensions over immigration in Durban. 

On October 8, violent protests linked to concerns about undocumented immigration and asylum applications broke out in the city's central business district.

During the unrest, at least 14 vehicles were set alight, while a lodge and a warehouse were partially damaged, according to police. Three foreign nationals were arrested in connection with the alleged assault of a protester before the violence.

South Africa has experienced protests over immigration and the asylum system in recent months. 

Authorities have urged residents to avoid violence and address grievances through lawful channels.