BALI (REUTERS) - Bali is known for its natural beauty.

Right now though that is proving more of a problem than a pleasure for tourists, thousands of who have been stranded since Monday when the airport closed. They received some much-needed good news on Wednesday: The airport reopened at 3pm local time on Wednesday, Indonesia's air navigation agency said. The airport had been closed since Monday.

But authorities are warning a major volcanic eruption on Mount Agung is still imminent.

The head of mitigation of PVMBG, Gede Suantika, says: "The activity remains high and the volcanic ashes column has risen 3,000 metres above the mountain's crater and the ashes are blowing towards the west.

The airport's closure had disrupted more than 400 flights and stranded tens of thousands of passengers.

Each day of closure cost airlines an estimated US$5 million (S$6.72 million) in lost revenue.

That has led many of them to offer travel to other destinations and even bus and ferry transport off the island.

Stranded tourist from France Yannick Puechlong says: "We've received correct information from the authorities.

They've informed us well on a day to day basis, but what can we do? It's nature so we can't do anything about it. For once we can't do anything."

Some tourists though are making the most of being grounded, even attempting a better view despite the fact around 100,000 people living near the volcano have been ordered to leave.

Sebastian Meier, a German tourist stranded in Bali, says: "They cancelled our flight, so we want to see why."

Mount Agung last erupted in 1963, killing 1,000 people and destroying several villages.

Experts warn a similar sized eruption this time could send rocks bigger than a fist flying up to 8 km.

Good reason, perhaps, to be safe rather than sorry.