"Two hundred twenty two people are dead, 843 people are injured and 28 people are missing," said Sutopo Purwo Nugroho, Indonesia's national disaster agency spokesman.
Casualties are expected to rise.
The Meteorology, Climatology and Geophysics Agency (BMKG) reported an eruption of the Krakatoa volcano about 9 p.m. Saturday local time, and the tsunami struck a short time later, about 9:30 p.m.
“The cause of the tsunami was due to a combination of undersea landslides after the eruption of Mount Anak Krakatoa and the tidal wave caused by the full moon," according to BMKG. However, the Indonesian Geological Agency said that they can't confirm if the tsunami was triggered by the eruption of Krakatoa, since that mountain has been erupting since last June – with even greater strength – and never caused a tsunami.
The chief of the Geological Agency, Rudy Suhendar, told VOA's Indonesian Service that it was still investigating what caused the tsunami.
The casualties occurred in three regions -- South Lampung in Sumatra and the Serang and Pandeglang regions of Java, west of the capital Jakarta -- along the Sunda Straits, Sutopo Purwo Nugroho, a spokesman for the National Disaster Mitigation Agency (BNBP), said in a statement.
Hundreds of homes, nine hotels and more than 350 boats were damaged, BNBP said Sunday, along with dozens of cars and other vehicles.
Jakarta resident Suhada was fishing on Carita Beach and visiting his family for the weekend when he ran from what he described as three waves between 10 and 11pm Saturday night. Suhada was able to flee to higher ground with his family.
"Thank God I could save my family," he told VOA's Indonesian service.
Disaster agency head Endan Permana told local media that many people were missing in tourist locale Tanjung Lesung, Banten province, near Jakarta.
Indonesian President Joko Widodo has ordered government agencies to respond quickly to the disaster.
"The Ministry for Social Affairs and the chief of the military are already on the ground," he said.
The Red Cross said Banten is one of the "worst affected areas." The aid organization, however, said it was able to dispatch "relief goods" from its Banten warehouse, including water, tarpaulins, cleaning equipment, plus family and hygiene kits.
U.S. President Donald Trump tweeted about the "unthinkable devastation" caused by the tsunami, adding that "We are praying for recovery and healing. America is with you!"
On September 28, a quake and tsunami that hit near the city of Palu, on the island of Sulawesi, killed more than 2,500 and displaced about 70,000.
On December 26, 2004, an earthquake in the Indian Ocean triggered a tsunami that killed 226,000 people in 13 countries, including more than 120,000 in Indonesia.