Crime scene experts at the scene at a Verulam Mosque after unknown armed men attacked the place. Picture: Doctor Ngcobo

Johannesburg - A device discovered in a mosque near Durban where worshippers were attacked by armed men last week has been confirmed as explosive, police said on Monday.

The device was discovered on Sunday three days after the attack at the mosque by three men armed with guns and knives. One person was killed after his throat was slit, and two others were injured.

"We had a meeting with the explosive unit members who briefed us on the device they had taken away yesterday. They confirmed that its mechanism is explosive," Simphiwe Mhlongo, a spokesman for the Directorate for Priority Crime Investigation told eNCA television.

"But at this stage they haven't gone through analysing what chemicals it is made of."

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Mhlongo said investigations were continuing.

South Africa is racked by violent crime and social strife rooted in poverty and glaring income disparities, but it is seldom associated with the Islamist militancy seen on other parts of the continent.