JOHANNESBURG, April 17 (Reuters) - Zimbabwean opposition leader Morgan Tsvangirai said on Thursday he had called on the regional organisation SADC to lead a new mediation effort in his country.

After saying South African President Thabo Mbeki should be removed as a mediator, Tsvangirai said he had asked Zambian President Levy Mwanawasa to launch a new initiative.

Mwanawasa is chairman of the Southern African Development Community (SADC).

"I have made a specific request to President Mwanawasa to say that he needs to lead a new initiative, given the extraordinary situation we are facing. An initiative that will expand beyond President Mbeki," Tsvangirai said.