(AFP) - Madagascar's longtime former leader Didier Ratsiraka, a naval officer and instigator of a socialist revolution on the Indian Ocean island, died Sunday morning aged 84, president Andry Rajoelina announced.

"The Malagasy have lost an illustrious patriot," Rajoelina posted on Twitter.

The cause of death was not immediately disclosed.

Nicknamed "Deba", Malagasy for 'bad guy' and 'boss', Ratsiraka was in power from 1975 until 1991 and returned for another stint from 1997 to 2002.

When he first came to power, he practised a form of Marxism and had close ties to North Korea's Kim Il Sung, Cuba's Fidel Castro and the Kremlin.

But economic setbacks and pressure for greater political openness amid allegations of widespread corruption brought a new liberalism, eventually forcing his resignation in 1991.

General strikes paralysed the country in the run-up to his leaving office as thousands of people gathered for months to protests his autocratic regime.

The situation turned violent when guards opened fire on a peaceful march at the presidential palace, killing more than 100 people. Ratsiraka defended the assault by the soldiers as self-defence.

In 1992, the introduction of a new constitution put an end to the unrest and Albert Zafy, who had led a transitional authority, won the ensuing presidential polls.

Four years later, Ratsiraka returned to power following Zafy's impeachment for violating the constitution.

Violence broke out again in late 2001 when Ratsiraka sought re-election against his main rival the Antananarivo mayor and entrepreneur Marc Ravalomanana.

The first-round results gave neither more than 50 percent of the votes.

Ravalomanana refused to organise a second round of voting, while Ratsiraka declined to concede defeat, plunging the country into seven months of violence and chaos.

The impasse split the nation in two -- with two capitals, two governments, and a divided army -- until Ravalomanana was officially proclaimed president in April 2002 and sworn in on May 6, with Ratsiraka still disputing the result.

The following July, Ratsiraka fled into exile in France before returning to Madagascar briefly in 2011, kissing the ground and doing press-ups at the airport to announce his arrival. He finally fully settled in the country in 2013.

In 2003, Ratsiraka was sentenced in absentia to five years in jail for threatening state security and 10 years for embezzling public funds. The sentences were later overturned.

Under the rule of the former leader with a gift of the gab, Madagascar became one of the poorest countries in the world, seeing its education system fail in the 1980s.

In 2013, he planned a political comeback but was struck off the list of candidates contesting the island's presidency.

© Agence France-Presse