Antananarivo  - The showdown between Madagascar's President Marc Ravalomanana and the capital's mayor Andry Rajoelina continued over the weekend, after Rajoelina declared he was taking over the running of the Indian Ocean island.

Until the opposition's demands for the installation of a transition government had been met, the 34-year-old mayor said Saturday, the security forces and government ministries should take their orders from him, and not Ravalomanana.

Ravalomanana, 59, who has been in power since 2002, made clear for his part he had no intention of stepping aside after a week of unrest, in which over 100 people were killed.

"I am still the president of the country. I am doing what is necessary to develop Madagascar," he told a hastily convened press conference Saturday.

The turmoil in Madagascar, a large island off south-east Africa populated mainly by poor subsistence farmers, is expected to be discussed at this week's meeting of African Union leaders in Addis Ababa, Ethiopia.

Ravalomanana will not attend. His prime minister is leading the Malagasy delegation.

On the eve of the summit the president of the African Union Commission, Jean Ping, issued a warning Saturday that "any unconstitutional changes in Madagascar would be condemned."

Rajoelina has called for ministries to remain closed to allow him to begin the task of forming a transitional government. He has also called for another rally on Monday.

The last combined strike and demonstration in Antananarivo a week ago ended in deadly riots and widespread looting. Police and soldiers shot dead several demonstrators and looters, dozens of other alleged looters died when they became trapped in a burning shop and more died in a stampede.

In an indication that the momentum may be subsiding however, only about 25,000-30,000 people attended Saturday's rally in Antananarivo - less than half the number that demonstrated five days earlier.

The opposition accuses Ravalomanana, an ex-mayor of Antananarivo and a self-made millionaire, of clamping down on media freedom, of transforming some of his businesses into monopolies and of failing to do enough to tackle poverty, among other charges.

Western donors have been trying to broker talks between the president and mayor, but with no success as yet.

The standoff between Ravalomanana and Rajoelina began in December when the state shut down the mayor's radio and television station for broadcasting an interview with Ravalomanana's sworn foe, ex-leader Didier Ratsiraka, whom he defeated in 2001 elections. dpa