Residents caught in Mount Agung’s danger zone have been fleeing in their thousands to the safer regions of the tourist hotspot.

Hastily built refugee shelters sprung up in the shadow of the volcano today, with mother and children seeking refuge.

Yesterday health and safety volunteers were seen tirelessly handing out ash masks in case Bali’s tallest volcano erupts for the first time in 50 years.

Mount Agung reared its ugly head this week on Tuesday, when it spewed a thick plume of smoke over the island.

One volcanologist has now warned the volcano has entered an “eruptive” period, casting a shadow of doubt on Bali’s future.

Joachim Gottsmann, professor of volcanology at Bristol University, told Express.co.uk: “From what I have seen in video coverage yesterday is that a white plume was visible.

“This indicates that the eruption was likely not magmatic. Many eruptions at volcanoes such as Agung start with what is called phreatic activity.

“Often but not always magmatic eruptions ensue after a period of phreatic activity.”

Phreatic eruptions occur when underground water passes over hot lava or magma, resulting in a ticking time bomb of dangerous gases and steam.

Professor Gottsmann said it not uncommon for magmatic eruptions to follow, and Agung’s increased activity this month could lead too further eruptions within weeks or months.

He said: “Magmatic means that molten rock is either erupted explosively with a dark eruption cloud or effusively in the form of a lava flow.

“All these eruptive activities can occur within short periods of time. An eruptive period may hence have several discreet eruptions.”

A sense of urgency was felt on the island yesterday – demonstrated in a powerful photo of a volunteer fitting a face mask on a little boy in Rendang district.

Elsewhere volunteers were seen walking through a traditional marketplace, handing out ash masks to vulnerable locals.

But despite the threat of the Bali volcano, Bali’s Tourism Office (BTO) is certain that the island will continue to attract scores of tourists.

BTO head AA Gede Yuniartha Putra said that Bali has seen a 25 per cent increase in tourist arrivals since September since the volcano first rumbled.

He told the Bali Post: “Until October, we’ve already reach around 5 million of our target of 5.5 million. And that’s with two more months in the year. 

“Per day, on average, there are 15,000 tourists coming to Bali. 

“In one month, that means 450,000 tourists, so that’s 900,000 for two months. So we can exceed the target.”

The Bali volcano first awoke from a deep slumber on September 22, when a period of intense seismic activity left the Pacific Island on high alert.

Authorities quickly raised the danger level to 4 – the highest possible – but have since dropped it down to level 3. But the threat still remains.

The resulting panic two months ago forced more than 140,000 resident to flee their homes for refugee shelters. Over 100,000 are still displaced.

With plumes of white steam continually steaming out of the volcano’s crater, Indonesia’s National Disaster Management Agency issued an exclusion zone up to 7.5 kilometres from the summit.

Spokesman Sutopo Purwo Nugroho said: “The status is still the same - level three.

”Volcanic activities have not shown any increase in earthquakes.”

Mount Agung and Indonesia sit in the incredibly volatile Ring of Fire – a long chain of 450 volcanoes and earthquake sites that stretch across the Pacific Ocean.

The last time Agung erupted in 1963, the volcano produced an estimated 280 million cubic metres of pyroclastic flows, killing over 1,100 people.