Flights could be affected if any volcanic ash invades Bali airspace, but local authorities are urging calm and vigilance.
Evacuees stay at an emergency shelter in Klungkung, Bali, Indonesia, after the start of eruption of Mount Agung on Tuesday, with an ash cloud rising 700 metres above the summit.
"The eruption is still ongoing".
Bali's Mount Agung volcano erupts: Bali's Mount Agung erupted at around 5pm yesterday, with the black smoke reaching a height of more than 700m from the peak.
But the alert level has not been addressed to the extent that "it is not a rash", said the Centre for volcanology and management of geological hazards.
"Right now, this is not a serious eruption, but of course this can change".
Phreatic eruptions also took place during the catastrophic eruption of Krakatoa in Indonesia in 1883, which killed 40,000 people.
"It is expected that all communities living around Mount Agung and on the island of Bali (should) immediately prepare a mask to cover the nose and mouth, and (have) eye protection as an effort to anticipate the potential danger of volcanic ash", a government statement said.
All airlines said on Wednesday morning flights in and out of Bali are operating as scheduled, but Jetstar Airways claims that could change if the smoke continues to billow.
The mount Agung, which has a little more than 3000 meters above sea level and is situated approximately 75 kilometres of the main tourist destinations of Kuta and Seminyak, growls since the month of August and could erupt for the first time since 1963.