JAKARTA, Indonesia — A frantic search was underway on Sunday for survivors of a tsunami in Indonesia’s Sunda Strait that struck without warning on the country’s two most-populous islands, killing at least 222 people, injuring more than 800 others and destroying hundred of buildings.
It was the second deadly tsunami in Indonesia this year, capping what will be the country’s worst year for disasters in more than a decade, with earthquakes, floods, fires and an airline crash that together have killed more than 4,500 people.
The tsunami struck about 9:30 p.m. on Saturday, when many Indonesians were at the beaches on western Java and southern Sumatra celebrating a long Christmas weekend.
Officials said they think that the tsunami — with a wave nearly 10 feet high that hit the coast — had been caused by an undersea landslide that was set off by volcanic activity on the island of Anak Krakatau.
There was no seismic activity in the area, which might have prompted a tsunami evacuation alert and saved lives, the officials said.
“There was no tsunami warning,” said Rahmat Triyono, earthquake and tsunami chief at Indonesia’s Meteorology, Climatology and Geophysics Agency. “There was no earthquake.”
The tsunami damaged or destroyed at least 556 homes, nine hotels, 60 small shops and 350 boats, said Sutopo Purwo Nugroho, the spokesman for Indonesia’s disaster management agency.
Officials put the number of injured at 848 and the missing at 28.
Mr. Sutopo noted that Indonesian officials were unable to detect the tsunami and provide a warning because “we do not have a tsunami early-warning system that’s triggered by underwater landslides and volcanic eruptions.”
“What we have,” he said, “is early warning based on earthquake as a trigger.” He added that the challenge is to develop a warning system that recognizes underwater landslides and volcanic eruptions.
The band, Seventeen, was playing its second song of a set when the wave burst through a backdrop behind the stage, crashed into the drummer, his drum set and the other musicians, and swept the stage into the audience.
The group reported that the bass player and the road manager had been killed. The lead singer, Riefan Fajarsyah, fighting back tears in an Instagram post, said that his wife, two other band members and a crew member were missing.
The band was performing at a gathering for families of employees of Perusahaan Listrik Negara, the state electricity company. Company officials said that 14 people attending the event had died and that 89 were missing.
The area hit hardest was Pandeglang regency in Java’s Banten Province, site of Tanjung Lesung Beach. The area is popular with visitors from Jakarta, the capital. Videos and photos from Pandeglang showed extensive damage, with houses crushed and at least one car overturned.
One video showed a police officer rescuing a 5-year-old boy from a damaged home in Banten.
Officials said the road from Pandeglang to the nearby regency of Serang had been cut off, hampering rescue efforts. Dozens were also killed across the Sunda Strait in Sumatra.
Indonesia, an archipelago of more than 17,000 islands, sits in an active volcanic and seismic area known as the Ring of Fire.
The Sunda Strait connects the Java Sea and the Indian Ocean and lies between Java, the country’s most-populous island, and Sumatra, the second-most populous.
Anak Krakatau, or the Child of Krakatau, emerged nearly a century ago from the volcanic crater of Krakatau, also called Krakatoa, which erupted in 1883 in one of the largest such events in recorded history.
The volcanic island has been growing steadily ever since, and in recent weeks has been erupting frequently. Officials said they would investigate whether volcanic activity had set off an undersea landslide that caused the tsunami.
“We don’t know what caused the tsunami yet,” said Mr. Rahmat of the meteorology agency. “We suspect it was caused by the Anak Krakatau activities.”
The biggest disaster to strike Indonesia in modern times was the Indian Ocean earthquake and tsunami that hit a dozen countries on Dec. 26 in 2004. In Indonesia, it obliterated much of the city of Banda Aceh, on the northern tip of Sumatra, and killed about 225,000 people.
In September this year, a 7.5-magnitude earthquake struck the island of Sulawesi, setting off an underwater landslide and causing a tsunami that struck the city of Palu and surrounding areas. More than 2,100 people died.
In August, a 7.0 magnitude earthquake hit Lombok island, killing more than 550.
The death toll from disasters in Indonesia this year is the worst since 2005, when a 6.3 magnitude earthquake struck the city of Yogyakarta on Java island, killing more than 5,000 people.