Two other people were injured.
Police investigators collect evidence at a mosque where three men were attacked in Ottawa, South Africa, May 10, 2018.
Three men stormed a Verulam mosque on Thursday afternoon‚ slitting the throats of at least two people and stabbing another.
Attackers stabbed victims during midday prayers north of the city of Durban then set the mosque on fire.
"They further set certain rooms alight and fled in their getaway vehicle", police spokeswoman Nqobile Gwala said in a statement.
"The motive of the attack is unknown at this stage".
Paul Herbst, spokesman for the private IPSS medical rescue service, told AFP that the imam had his throat slit and passed away a few hours after the attack.
3 takeaways from Game 5 vs. Warriors
The Warriors have averaged 113.1 points per game in the regular season and playoffs combined, while the Rockets averaged 112.1. On one side, you have three Warriors All-Stars who are now four years into this dominating run with Curry, Thompson and Green.
The KwaZulu-Natal South African Police Service (SAPS)'s Col Thembeka Mbhele confirmed the incident.
"We reiterate and emphasise the core Islamic teaching and principle of "respect for all human beings", Shaykh Isgaak Taliep, secretary general of the Muslim Judicial Council, said. Paramedics were called to the scene to attend to the men.
The Ethekweni Fire Department was on the scene. "The other two are in critical condition", said Prem Balram, a spokesperson for Reaction Unit SA, which was first on the scene.
A section of the mosque was set ablaze and smoke was billowing from the side of the building, Balram said.
"This kind of attack on three innocent people is totally unjustified".
"A mosque is a religious institution and South Africa's Constitution guarantees and protects the right to religious practices", said chairperson of the committee Francois Beukman. About 1.5 percent of the country's population is Muslim.
The attack came shortly ahead of the Muslim fasting month of Ramadan, which begins around May 16.