DAR ES SALAAM (AFP) - Tanzanian President John Magufuli died Wednesday aged 61 from a heart condition, his vice president said, after more than five years of divisive, authoritarian rule capped by his refusal to take Covid-19 seriously.

Mr Magufuli, popularly nicknamed the "Bulldozer", had been missing from public view for almost three weeks, fuelling wild rumours of his ill health, with opposition leaders claiming he had contracted the virus.

"It is with deep regret that I inform you that today on the 17th of March, 2021 at 6:00 pm we lost our brave leader, the President of the Republic of Tanzania, John Pombe Magufuli," said vice-president Samia Suluhu Hassan.

She said Mr Magufuli had died of a "heart condition", which he has suffered from for a decade, at a hospital in Dar es Salaam.

He had first been briefly admitted to the Jakaya Kikwete Cardiac Institute on March 6, but was subsequently discharged, Ms Hassan said.

But Mr Magufuli had again felt unwell and was on March 14 rushed to hospital, this time to the Emilio Mzena Memorial Hospital in Dar es Salaam.

Ms Hassan announced a 14-day mourning period.

Mr Magufuli last appeared in public on Feb 27, and the fervent Catholic had missed three Sunday services, where he would often address the congregation, sparking concern.

Opposition leader Tundu Lissu cited sources saying that the president had caught the virus, as demands grew for information on his whereabouts and rumours took off that Mr Magufuli was seeking treatment outside the country.

Lissu, who ran and lost against Magufuli in a disputed October election, said the 61-year-old strongman leader had succumbed to coronavirus and the government was "lying even now that he is dead".

"Magufuli died of corona," said Lissu from Belgium in an interview broadcast on Kenyan network KTN News, citing his sources. The claim could not be independently verified.

Magufuli's supporters mourned his death after his weeks-long absence, and signalled an uncertain political road ahead.

"I am saddened personally. I've lost hope because I relied on him as my leader, he was a leader of the poor and now we are wondering how things will be now that our leader has died," said 24-year-old Lewis, in Dar es Salaam, waiting for a bus.

British Prime Minister Boris Johnson said on Twitter he was "sorry to hear" that Mr Magufuli had passed away.

"My thoughts are with his loved ones and the people of Tanzania."

Anti-corruption crusader

Mr Magufuli was first elected in 2015 as a corruption-busting man of the people, endearing him to a population weary of graft scandals.

However, a slide into authoritarianism, which saw a crackdown on the media, civil society and opposition, raised alarm among foreign allies and rights groups.

His re-election last October was dismissed by the opposition and some diplomats as a sham, over alleged rigging, the blocking of foreign media and observer teams and an oppressive military presence.

Analysts said that Mr Magufuli had dealt a crushing blow to democracy in one of Africa's most stable nations.

Mr Magufuli also expanded free education, rural electrification and invested in infrastructure projects such as railways, a hydropower dam set to double electricity output and the revival of the national airline.

His government also passed a raft of laws to increase Tanzania's stake in its mineral resources and demanded millions of dollars in back taxes from foreign mining companies.

But it was Mr Magufuli's handling of the coronavirus pandemic which cast his leadership style into sharp relief.

He was one of a handful of world leaders, alongside former US President Donald Trump and Brazil's Jair Bolsonaro, who scoffed at the virus, championing alternative medicines.

Mr Magufuli called for prayer instead of face masks, before stopping the publication of statistics in April 2020 when the country had recorded a total of 509 cases and 16 deaths.

Tanzania became an outlier in a region which quickly implemented lockdowns, night-time curfews and travel restrictions to stem infections.

In May last year he revealed he had submitted a variety of fruit and animals to be tested for the virus and that a papaya, quail and goat tested positive, charging there had been "sabotage" at the national laboratory.

'There is no Covid-19'

Mr Magufuli later claimed prayer had saved the country from Covid-19.

"That's why we are all not wearing face masks here. You think we don't fear dying? It's because there is no Covid-19," he said.

However by February, as illness soared and the vice president of semi-autonomous Zanzibar was revealed to have died from Covid-19, Mr Magufuli conceded the virus did in fact exist.

Nevertheless he warned his health ministry not to rush into procuring vaccines, saying they were "dangerous".

Under Tanzania's constitution, Ms Hassan will become the country's first female president and will consult the ruling Chama Cha Mapinduzi (CCM) party over the appointing of a new vice president.

Mr Magufuli's death plunges Tanzania into political uncertainty, according to Prof Nic Cheeseman, professor of democracy at the University of Birmingham.

"The news of Magufuli's death will fundamentally reshape Tanzanian politics. Having dominated the political scene since his election, he leaves something of a political vacuum," Prof Cheeseman said.

"This will trigger fresh uncertainty and all eyes will be on internal CCM politics to see what deals have been struck in the ruling party about the balance of power after the transition."