HUNDREDS of people have been killed and almost a thousand more injured after a tsunami hit tourist beaches and coastal areas on Indonesia's Sunda Strait on Saturday.

The deadly wave is believed by officials to have been caused by Anak Krakatau, a volcanic island in the Sunda Strait. Here's everything known so far...

Hundreds of people have been killed and almost a thousand injured after a tsunami caused by a volcano struck the coast of Indonesia
Where is Krakatoa?
Krakatoa is a volcanic island situated in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung.

The name is also used for the surrounding island group comprising of the remnants of a much larger island of three volcanic peaks which were obliterated in the 1883 eruption.

Ahead of the cataclysmic 1883 eruption, a series of lesser eruptions began on 20 May 1883. The volcano released huge plumes of steam and ash lasting until late August.

On 27 August a series of four huge explosions almost entirely destroyed the island.

The explosions were so violent that they were heard 1,930 miles away in Perth, Western Australia, and the island of Rodrigues near Mauritius, 3,000 miles away.
The pressure wave from the final explosion was recorded on barographs around the world.

Several barographs recorded the wave seven times over the course of five days: four times with the wave travelling away from the volcano to its antipodal point, and three times travelling back to the volcano.

This means the wave went all around the globe three and a half times.

The sound of the eruption was so loud it was reported that if anyone was within ten miles, they would have gone deaf.

The death toll recorded by the Dutch authorities was 36,417, although some sources put the estimate at more than 120,000.

Where is Anak Krakatau in Indonesia?
Anak Krakatau, translated as "Child of Krakatoa" is an island located in the Sunda Strait between the two islands of Java and Sumatra.

It was formed after its 'parent volcano' Krakatoa erupted in 1927, with Anak Krakatau breaking water in 1930.

The Sunda Strait connects the Java Sea to the Indian Ocean.

The region is home to many popular tourist destinations that were hit, including the Tanjung Lesung beach resort in the west of Java island.

Why did the volcano cause a tsunami?
When volcanoes erupt, hot magma presses underground and can move and break through colder rock. This can trigger a landslide.

But because the volcano is underwater, the water is pushed as it moves, causing a tsunami on the surface of the sea.

The Anak Krakatau volcano has been active in recent months.

Indonesia's geologic agency said the volcano erupted for two minutes and 12 seconds on Friday, forming an ash cloud 400 metres above the mountain.

It recommended nobody be allowed within two kilometres of the crater.

How many people have died?
At least 281 people have been killed and 843 injured, with this number expected to rise.

Along with tourist beach resorts, deaths have been reported in the Pandegland and Serang on Java, and Lampung province on Sumatra.

Footage of a band playing at a beach was circulated on social media, with its singer confirming the band's bassist and road manager had died, with the other members missing.