Police have killed three gunmen who are apart of a gang holding several shoppers hostage on Thursday at a Checkers supermarket in Montclair, Durban paramedics said.

Netcare 911 spokesperson Chris Botha said the gunmen shot dead a man in his 50s and threw his body out of the store.

"There are still gunmen in the store and police are trying to shoot them, we don't know how many are left, or how many innocent shoppers there are," he said.

An elderly shopper also suffered a massive heart attack because of the stressful situation, and another staff member was hysterical from a nervous breakdown. Both were let out of the store by police.

Botha said two more people might have been shot inside the store as he had heard more gunshots.

The supermarket is on the corner of Kenyon Howden Road.