Ethiopian Prime Minister Meles Zenawi, a regional strongman in the volatile Horn of Africa who ruled with an iron fist for over two decades, has died in hospital in Brussels after a long illness, officials said yesterday.

Mr Meles was regularly singled out as one of the continent’s worst human rights predators

Mr Meles, a former rebel who came to power in 1991 after toppling the bloody dictatorship of Mengistu Haile Mariam, set Ethiopia on a path of rapid growth and played a key role in mediating regional conflicts but also drew criticism for cracking down on opponents and curtailing human rights.

The 57-year-old – a key Western ally in a region home to Al-Qaeda-linked groups – had not been seen in public since the G20 summit in Mexico in June.

European Commission spokesman Olivier Bailly said Mr Meles had died in Brussels but the Ethiopian government said only that he had died abroad.

“Prime Minister Meles Zenawi passed away yesterday evening at around midnight,” said government spokesman Bereket Simon, adding he had been “struggling to be healthy in the last year”. “He had been recuperating well but suddenly something happened and he had to be rushed to the ICU (intensive care unit) and they couldn’t keep him alive,” he added.

Deputy Prime Minister Hailemariam Desalegn, 47, who has also been Foreign Minister since 2010, will take over interim power, Mr Bereket said.

Unlike many core members of the ruling party, Mr Hailemariam does not hail from the far north of the country but from the Southern Nation, Nationalities and People’s Region, the most populous of Ethiopia’s nine ethnic regions.

World leaders offered high praise for Mr Meles – British Prime Minister David Cameron hailed him as “an inspirational spokesman for Africa” – but rights groups said his death offered a chance to end a brutal crackdown on basic freedoms.

Mr Meles was regularly singled out as one of the continent’s worst human rights predators and Amnesty International called on new leaders to end his government’s “ever-increasing repression”.

Human Rights Watch called for the next administration to repeal a much-criticised 2009 anti-terrorism law, under which multiple opposition figures and journalists, including two Swedes, have been jailed for lengthy terms.

Ethiopia has declared a state of national mourning, but has not fixed a date for a funeral, said Mr Bereket, adding that “everything is stable” in the country.

Mr Meles also played a key role in brokering peace efforts between the two warring Sudans.