Hundreds of tremors and blowouts of lava marked a significant increase from recent months.

The explosions rattled the windows of hotels on nearby Java island, according to the head of the government's nearby volcano monitoring post.

Anton Tripambudi told Tempo that billowing clouds of white and grey smoke that spewed from the mountain reached as high as 2,000 feet into the sky.

The volcano roared back to life in November 2007, producing frequent and spectacular eruptions since then that have attracted tourists from around the world.

Anak Krakatau is the volcanic island that replaced the famed Krakatoa, which was obliterated by an 1883 eruption that killed 36,000 people from resulting tsunamis.

Ash from the greatest explosion in recorded history darkened over half the planet.

Photo: Vulcanological Survey of Indonesia