At least 20 people have been killed and 165 injured after a tsunami hit the coast around Indonesia's Sunda Strait, government officials say.

The country's disaster management agency says two people are missing, and dozens of buildings were damaged.

It says the possible cause of the tsunami were undersea landslides after the Krakatoa volcano erupted.

The Sunda Strait between the islands of Java and Sumatra connects the Java Sea to the Indian Ocean.

The deaths were reported in the Pandeglang, South Lampung and Serang regions.

Officials warn that the death toll is likely to rise further. The disaster management agency said high seas as a result of the full moon may also have contributed to the strength of the wave.

Eyewitness Oystein Lund Andersen, who was on the beach at the time, told the BBC two waves had hit, with the second much bigger than the first.

Mr Andersen, a Norwegian professional volcano photographer, said he had rushed to the hotel where his family were staying, and they later went to a higher ground in a forest.

He added that there had been heavy eruption sound prior to the tsunami.

Footage posted by the head of disaster agency showed the aftermath of the tsunami, with flooded streets and an overturned car.

He had earlier posted footage of water rushing in and local residents trying to flee in panic.

Emergency officials are now investigating whether the tsunami was caused by Anak Krakatoa, a volcanic island in the Sunda Strait.