A protest by Johannesburg emergency services staff at the Roodepoort call centre is putting residents' lives at risk, the Democratic Alliance said on Friday.

Calls to the call centre went unanswered, "causing further injuries and deaths", spokesperson Jack Bloom said.

"Strong action is needed as it is completely unacceptable that emergency calls are not getting through and lives could be lost," he added.

Ambulance workers and firefighters downed tools on Thursday in protest against poor working conditions and wages.

"I spoke to three reliable sources within the EMS (Emergency Management Services) who say that the situation spiraled out of control when a union meeting held yesterday decided on urgent mass action.

"One of the issues on the table has been the appointment of personnel from outside rather than within and the salary scales that are offered to such appointments," Bloom said.

It was not yet known which union was involved. EMS spokesperson Nana Radebe referred all enquiries to City of Johannesburg spokesperson Nthatisi Modingoane.

Modingoane could only say that officials had been dispatched to the call centre to assess the situation.

"We will then release a media statement," he said.

Sapa