Guinea-Bissau's ex-President Kumba Yala, who ruled the former Portuguese colony from 2000 until 2003, has died.

A former philosophy teacher, Mr Yala won presidential elections in 2000 following a bitter civil war in the late 1990s.

He was ousted three years later in one of the West African nation's many military takeovers.

His death at the age of 61 comes 10 days before elections intended to draw a line under the latest coup, in 2012.

Guinea-Bissau is one of the poorest countries in the world and has been further destabilised by the booming illegal drugs trade from Latin America, which uses it as a staging post for the European market.

Mr Yala, who headed the opposition Party for Social Renewal (PRS), had recently announced his intention to retire from politics.

He had not given his backing to his party's presidential candidate in the forthcoming polls, instead voicing support for an independent candidate.

Correspondents say that the former president was known for his nationalism, fiery speeches and trademark woollen hat.

A statement from the country's military hospital said Mr Yala had died of a sudden cardiac arrest, Reuters news agency reports.