Lisbon  - Guinea-Bissau's interim President Raimundo Pereira praised slain president Joao Bernardo "Nino" Vieira as having represented "humanist values," condemning his killing as an "affront to the republic" at a state funeral for Vieira on Tuesday.

The 69-year-old president was shot dead in his home a week ago by soldiers angered by the killing of army chief Tagme Na Wai, Vieira's long-time rival, a few hours earlier. Tagme was buried over the week- end.

The parliament plenary room room where Vieira's coffin lay-in- state was so crowded that some diplomats could not sit down.

Vieira's widow Isabel, dressed in black, was seen in public for the first time since her husband's death.

People coming to pay their respects to Vieira included representatives of African countries, the United Nations and the European Union.

However, no African heads of state were in attendance, in what analysts interpreted as a signal of concern over the continuing instability in Guinea-Bissau.

The ceremony was delayed by nearly 90 minutes because a military plane bringing several of Vieira's children from Dakar did not arrive in time, the Portuguese news agency Lusa reported.

Pereira described the killings of Vieira and Tagme as an "affront to the institutions of the republic," warning that the country's long-running "military and economic crisis" prevented it from obtaining the international cooperation that it needed "more than ever."

As one of the political and military leaders who helped Guinea- Bissau become independent from Portugal in 1974, Vieira personified "humanist values," Pereira said.

Thousands of people followed Vieira's coffin along the 5-kilometre route to the Catholic cemetery, but soldiers kept unauthorized people off cemetery grounds, where Vieira was laid to rest in the presence of government and diplomatic representatives.

Guinea-Bissau is now to stage elections within 60 days.

Vieira was the president of the West African country of 1.5 million citizens on and off for 23 years.

It was "essential" for the former Portuguese colony to "enter a new cycle in its political life," said Portuguese foreign affairs secretary of state Joao Gomes Cravinho, who spoke to Lusa in Cape Verde before attending Vieira's funeral.

Guinea Bissau, one of the world's poorest countries, has a history of coups, and is also now a key hub for South American drug smuggling cartels. (dpa)