Johannesburg - The number of deaths from a new Lassa-type virus has risen to four in South Africa, doctors confirmed to state radio Wednesday.

The latest death was a woman who died from the arenavirus, which can cause internal bleeding and mainly affects rodents.

The first victims of the new virus were a woman from Zambia and her carers.

The symptoms of the virus are similar to Lassa fever: constant fever, infections and rashes.

Analysis of tissue samples from the first victims by a US laboratory indicated that the cause of death was a previously unknown virus. (dpa)