The former president “had a malaise on Thursday night” and died in the early hours of the morning on Friday, his personal security chief Alfredo Malu, told AFP by telephone.
The government released a brief statement reporting that Yala had died of a heart attack and announcing a “special session of cabinet” at 9:00 am.
“He died at 2:00 am this morning. We took his body to the Bra military hospital” in the capital Bissau, a weeping woman member of the family said, asking not to be named.
Malu said that Yala’s sudden illness late on Thursday prevented him from meeting with candidates in his Party for Social Renewal (PRS) who are campaigning ahead of presidential and parliamentary elections due on April 13.
Born on March 15, 1953 to a family of peasant farmers in Pkon, a village near the northwestern town of Bula, Yala belonged to the Balanta ethnic group, the largest in the country, and was educated at home and in Portugal, the former colonial power.
Yala became a professor of philosophy and also acquired a law degree. He mastered Portuguese, Spanish, French and English.
When he turned to politics, he gained a reputation as a determined character who at first won the hearts of many of the people of Guinea-Bissau, which was born of a rebellion against the Portuguese and has since endured civil war.
Yala frequently appeared in public wearing a trademark red woollen bonnet, which is a distinction marking out the initiated men in the Balanta community. He won the nickname “Red Bonnet”.
He was elected civilian president in 2000 in a country where the all-powerful army pulls many strings and which has in recent years become a hub for drugs trafficking between South America and Europe.
Some of Yala’s policies began to cause political and social turmoil. Three years later, the military removed him from office in a bloodless coup. Later in life, he ran twice in polls to regain the presidency, but was unsuccessful.
Yala’s time in power was marked by strikes and protests over unpaid wages. He frequently sacked ministers in his government and emptied the state coffers. Public discontent eventually took hold in the army, in which Balantas play a major role.
The downfall of the once popular leader was widely applauded among the population, estimated at about 1.5 million by the World Bank in 2011.