The death toll started to rise Sunday after a tsunami struck the coast of Indonesia on Saturday night.
Officials placed the count at 222 dead and about 600 injured, according to reports.
The tidal wave sent water crashing 65 feet inland, sweeping away hundreds of homes, including hotels, government officials said.
The National Disaster Management Agency confirmed that the tsunami struck Saturday night, leaving dozens of buildings damaged and 20 people unaccounted for, on top of the escalating human toll.
The Meteorology and Geophysics agency, in a separate statement, said the cause of the tsunami could have been undersea landslides from Anak Krakatau, a volcanic island formed over years from the Krakatau volcano, which last erupted in October.
The Sunda Strait between the islands of Java and Sumatra connects the Java Sea to the Indian Ocean.
In September, at least 832 people were killed by a quake and tsunami that hit the city of Palu on the island of Sulawesi, which is just east of Borneo.
When Saturday's tsunami struck, many turned to social media with their reactions and descriptions of events.
"I had to run, as the wave passed the beach and landed 15-20m (meters) inland," Øystein Lund Andersen wrote on Facebook. He said he was taking photos of the volcano when he suddenly saw a big wave come toward him.
"Next wave entered the hotel area where I was staying and downed cars on the road behind it. Managed to evacuate with my family to higher ground through forest paths and villages, where we are taken care of (by) the locals. Were unharmed, thankfully."
Footage posted to social media showed a pop band named "Seventeen" performing under a tent on the beach as dozens of people sat at tables listening. In between songs, the stage lurched forward, throwing the band and its equipment into the audience.
In a statement, the band confirmed its bass player and road manager were found dead and that four other members of the group were missing.
“The tide rose to the surface and dragged all the people on site,” it said. “Unfortunately, when the current receded our members are unable to save themselves while some did not find a place to hold on.”
The worst affected area was the Pandeglang region of Banten Province in Java, which encompasses the Ujung Kulon National Park and popular beaches, the Disaster Management Agency said. Of the deaths, 33 were in Pandeglang, AP reported.
In the city of Bandar Lampung on southern Sumatra, hundreds of residents took refuge at the governor's office.
Fox News' Louis Casiano and the Associated Press contributed to this report.