The appeal was made at an extraordinary summit of the Southern African Development Community in Johannesburg.

The summit noted that political tensions on the Indian Ocean island had been getting worse.

Madagascar's political turmoil began as President Marc Ravalomanana was ousted amid street protests in March.

He was replaced by 35-year-old opposition leader Andry Rajoelina, who seized power with military backing.

The SADC summit in Johannesburg was called after officials suspended talks backed by the African Union and the UN on Tuesday, citing a lack of political will.

'Serious concern'

Participants in Johannesburg included South African President Jacob Zuma, and the leaders of Tanzania, Zimbabwe and Swaziland.

They nominated a respected former president of Mozambique, Joaquim Chissano, to lead mediation efforts by SADC and other bodies.

Marc Ravalomanana (l) is seeking support for a return to Madagascar

Tomaz Salomao, the executive secretary of the regional group, said in a final statement that there was "serious concern [about] the deterioration of the political situation in Madagascar".

"The extraordinary summit urges all stakeholders to commit themselves to peaceful negotiated settlement through dialogue and desist from any violent solutions and inflammatory statements," he said.

In his opening remarks on Saturday, Mr Zuma said: "We believe that peace will be achieved if all parties to the conflict are committed to the process."

Mr Ravalomanana is living in exile in South Africa, where he has been seeking international support for a return to Madagascar.

He was at the summit in an unofficial capacity, and held informal meetings on the sidelines.

Earlier this month Mr Ravolamana was sentenced in absentia to four years in jail for alleged abuse of office.

He has rejected sharing power with Mr Rajoelina, and suggested that a military solution should be considered - an option that had also been aired by the African economic bloc, Comesa.