ANTANANARIVO (AFP) - Madagascar's defence minister on Monday announced her resignation in protest at the police shooting of opposition supporters this weekend that left 28 dead and drew international condemnation. As the power struggle between President Marc Ravalomanana and opposition leader Andry Rajoelina escalated, Cecile Manorohanta said she did not want to remain in a government that condoned the shooting of civilians. "In this period of political crisis, I extend my condolences and moral support to the families who suffered losses," Manorohanta said in a statement read on the private radio channel Antsive. "As a mother, I do not tolerate this violence," she said. "It was agreed at government level that the security forces were meant to protect the population and its property.... After all that has happened, I decide as of now to no longer remain part of this government." She was promptly replaced in the cabinet by the chief of military staff, Mamy Ranaivoniarivo, a defense ministry spokesman told AFP. On Saturday Rajoelina, who was sacked as mayor of Antananarivo by his rival, organised a rally attended by 20,000 people where he outlined the new structure of his opposition movement, launching a "transition authority" and naming his own prime minister. Egged on by Rajoelina, 34, a few hundred demonstrators marched on a palace used by the Indian Ocean island's president in a bid to make it the headquarters of the opposition's parallel administration. Security forces guarding the presidential building opened fire on the crowd, killing at least 28 people and wounding 212, in one of the nation's deadliest political incidents in decades. In the capital's May 13 square, the venue of the opposition rallies, more than 5,000 mourners gathered for the funeral of four victims, their coffins placed on a stage above which were seen eight photos of other victims. "It was excessive. I had always remained neutral before Saturday, but I am no more now," said Thaina Randrianalison, a 26-year-old student. Senior government official Jules Randriamanatsika said: "I am not at peace with my conscience. I am going to the May 13 Plaza." Late last month at least 68 people died when an opposition protest deteriorated into rioting and looting in several spots across the country. While previous turmoil in Madagascar, one of the world's poorest nations, was politically motivated, observers have noted that the latest crisis is driven mainly by hunger. Rajoelina, a former DJ and savvy businessman, has upped the ante against Ravalomanana's regime in recent weeks, accusing the president of being a dictator starving his people. Rajoelina's protests had been losing steam until Saturday but the pressure was back on the regime after the shooting, with Monday's newspapers unanimously condemning a "bloodbath", a "butchery" or a "carnage". The opposition daily La Verite spoke of the shooting's "tragic toll, unprecedented in Madagascar's history". As bereaved families and other Madagascans marked a day of mourning called by Rajoelina Monday, the international community appealed for calm and justice. The United Nations called on the government to probe the shooting and prosecute those responsible while former colonial power France also reiterated its call for dialogue. UN chief Ban Ki-moon's envoy Haile Menkerios met Ravalomanana and was due to hold talks with Rajoelina late Monday. According to a statement issued by the president's office, Menkerios expressed "his desire to help Madagascar find a peaceful and democratic solution" to the crisis. African Union Commission chief Jean Ping also announced he was sending Amara Essy, the bloc's former commission president, to the Indian Ocean island to seek a solution to the country's crisis.