Addis Ababa, Jul 17 (IANS): It's a mystery absence that has created a lot of hush-hush talk here. Ethiopian Prime Minister Meles Zenawi has been missing from the African Union summit, fanning speculation about the health of the 57-year-old leader who has helmed the country since 1991.

Dozens of African leaders, ministers and diplomats who attended the two-day AU summit were surprised by Zenawi' absence as his government was hosting the continent's showcase diplomatic event.

"It 's unusual for someone as dynamic as Meles Zenawi to miss the summit," said a Kenyan diplomat, who did not wish to be named. Ethiopia's Deputy Prime Minister and Foreign Minister Hailemariam Desalegn stood in for Zenawi at the summit.

Benin's president and current AU chairman Thomas Boni Yayi said that the "unusual absence cannot go unnoticed, because we know that Mr. Meles is full of dynamism and leadership in our meetings".

Zenawi also could not attend the July 14 meeting of the New Partnership for Africa's Development (NEPAD), sparking speculation about his ill-health.

He was last seen in public at the G20 meeting in Mexico on June 19.

"He is critically ill and has been taken to a European country," said a diplomat. The rumours swirled even as an Ethiopian opposition group claimed that Zenawi had died.

The Ethiopian government rebutted such speculation, but admitted that he is ill and is being treated.

"There is no serious illness at all. It's minor only," Deputy Prime Minister Desalegn said in an interview in the Ethiopian capital, the seat of the 54-nation African Union. "As any human being, he has to get medication and he'll be coming back soon."

Over the years, Zenwai has carved reputation as a strong leader in charge of the Horn of Africa's most stable nation and a committed Africanist, representing the African view in international fora, including G8 meetings, Tony Blair's Commission for Africa and the climate change negotiations in Denmark in 2009. He is also the AU's spokesman on climate change.

In an e-mailed statement, the Ethiopian National Transitional Council, a Texas-based opposition group, said that Zenwai may have died in a Belgian hospital. According to The Ethiopian Review, an anti-government website, Zenawi was in the Saint-Luc University Hospital in Brussels.

The Ethiopian embassy in Brussels, however, dismissed the report as "false and wrong".

Educated in British universities, Zenawi led the Ethiopian People's Revolutionary Democratic Front (EPRDF) to help overthrow the communist government of Mengistu Haile Mariam in 1991 and has remained in power since then.