Two Australian tourists who climbed Bali's active Mount Agung volcano have been detained by the Indonesian police after the duo flouted rules prohibiting people from going within 8km of the volcano's crater ever since it erupted in November 2017.

According to the Bali police, the tourists, Ricky Tonacia, 34, and Jack Dennard, 26, had started climbing at around 2 am local time (7 pm GMT) on Thursday, 4 January.

The police chief said that his office had received a report stating that two foreign tourists were climbing the mountain, according to ABC television network.

Around eight hours later, when the two tourists descended, they were taken in for questioning by the police. They told authorities that they were not aware of the prohibited zone around the volcano, despite the fact that the 8km limit has been widely publicised throughout the island.

"We went to the gate at the border of the no-climbing danger zone, and we met two guides who were waiting for them to come back down from the top," the police chief said.

"The local military chief and I and some volunteers waited for them to come back and when they came back, we secured them afterwards at Selat Police Office, to get their statements."

The two men were later released and allowed to go back to their accommodation in Bali's Canggu district.

According to volcanologists, large eruptions could occur at any time, which is why no one is allowed to be near the mountain.

Meanwhile, back in November 2017, scientists published a report saying that a volcanic super-eruption with the potential to destroy our civilisation could take place much sooner than previously thought.

The previous estimates made by experts stated that massive eruptions are likely to occur roughly once every 45,000 to 714,000 years, which could be described as "comfortably longer than our civilisation".

One of the last known super-eruptions is said to have taken place 74,000 years ago in Indonesia.

Mount Agung volcano
The police have prohibited people from going close to the volcano's crater - File photo SONNY TUMBELAKA/AFP/Getty Images