(AFP) - Pope Francis this week urged Mauritius, a prosperous magnet for tourists and a global tax haven, to shun an "idolatrous economic model" that excludes the youth and the poor and damages the environment.

The Argentine pontiff's visit to the idyllic Indian Ocean island began with a mass attended by an estimated 100,000 faithful, ecstatically waving palm fronds and cheering "Francis, Francis".

While the island is a beacon of stability and relative prosperity, Pope Francis honed in on the struggles of the youth, who face growing inequality, unemployment and the scourge of drug abuse.

"It is a hard thing to say, but, despite the economic growth your country has known in recent decades, it is the young who are suffering the most. They suffer from unemployment, which not only creates uncertainty about the future, but also prevents them from believing that they play a significant part in your shared history," said the pope.

"Let us not allow those who deal in death to rob the first fruits of this land," he said, referring to drug dealers.

According to a Mauritius Drug Observatory report in 2018, the smuggling and use of drugs such as heroin, cannabis, cocaine and methamphetamine, has grown in recent years.

He continued this theme in a later address at the presidential palace, warning that the country's system of economic growth sidelined the young.

- 'Altar of speculation' -

Since independence in 1968, Mauritius has developed from a poor, agriculture-based economy, to one of Africa's wealthiest nations and financial services hub.

It has increasingly come under fire for helping global companies avoid paying taxes -- often in poor African nations -- and was in 2015 placed on a European Union tax haven blacklist.

General unemployment is low compared to the rest of the continent at 6.9 percent in 2018 according to the World Bank, but is high among the youth at 22 percent and inequality is seen to be rising.

Pope Francis urged Madagascar "not to yield to the temptation of an idolatrous economic model that feels the need to sacrifice human lives on the altar of speculation and profit alone, considering only immediate advantage to the detriment of protecting the poor, the environment and its resources".

According to the World Bank, one of the greatest challenges for the island is adapting to the effects of climate change -- which has worsened tropical storms and floods affecting it.

Some waited for the pope from before dawn, and many faithful were dressed in the yellow and white of the Vatican flag, coming from near and far.

"More than 3,500 of us came from Reunion" island -- about 175 kilometres (110 miles) -- from Mauritius, said a woman who identified herself as Josette.

-'Welcome migrants' -

Mauritius comprises four volcanic islands and lies roughly 1,800 kilometres (1,100 miles) off the eastern coast of Africa.

It is a melting pot of religions and ethnic backgrounds.

The population of 1.3 million is predominantly Hindu but has sizeable Christian and Muslim minorities.

About 30 percent of Mauritius is Christian, with most being Catholic.

The island was uninhabited when first visited by explorers in the Middle Ages. It was later briefly colonised by the Dutch, French and the British, and slaves from the wider region were introduced.

Now citizens have multi-cultural roots, from India, China, Europe, Africa and elsewhere.

Praising the island's diversity and rich history, the pope urged citizens to in turn "take up the challenge of welcoming and protecting those migrants who today come looking for work and, for many of them, better conditions of life for their families."

The pontiff's visit coincides with the 155th anniversary of the death of Father Jacques Desire Laval, a French priest sent to Mauritius to bring Christianity to former slaves. He died in Mauritius in 1864, and was beatified in 1979.

The Pope visited the mausoleum of Laval, known as the "Apostle of Mauritius" for his missionary work.

Every year about 100,000 pilgrims visit the tomb of Laval, northeast of Port Louis, on the night of September 8-9, to commemorate his death.

This year it was brought forward to September 7-8 to accommodate the Pope's visit.

The Mauritius visit was the last stop of the Pope's tour which has taken him to Mozambique and Madagascar, two of the world's poorest nations. He returns to Rome on Tuesday.

© Agence France-Presse