Rescuers hunted for survivors and victims under the rubble of hundreds of hotels and houses flattened by a deadly tsunami along Indonesia’s Sunda Strait with authorities warning the death toll may climb from the 373 already confirmed.

Most of the victims were local holidaymakers staying in the hotels and bungalows along the popular beaches in Lampung and Banten provinces, according to the National Disaster Mitigation Agency. More than 1,450 people were injured and dozens are missing after tsunami waves lashed the provinces late on Saturday, the agency said.

The latest in a series of natural disasters to strike Southeast Asia’s largest economy this year is set to pose a fresh challenge for President Joko Widodo as he works to assist the thousands of people displaced amid a presidential election campaign. The tsunami, coming ahead of the peak holiday season, may also hurt the all-important tourism industry and weigh on the nation’s currency, among the worst performers in Asia this year.

Indonesia’s meteorological agency previously suspected under-sea erosion triggered by volcanic activity of Mount Anak Krakatau, the disaster mitigation agency’s spokesman Sutopo Nugroho said. Authorities failed to pick up the signs of tsunami and alert residents, catching holidaymakers unawares and increasing the casualties.

The death toll could climb as searchers access more areas hit by the tsunami in Pandeglang, South Lampung, Serang, Tanggamus, Pesawaran regencies, Nugroho said.

Widodo, known as Jokowi, headed to the tsunami affected regions on Monday after ordering authorities to step up relief operations, according to an official statement. The president instructed the purchase of early warning system equipment by the met agency, known as BMKG, and to include disaster awareness into school curriculum.

‘The tsunami pattern in the Sunda Strait is beyond the BMKG prediction, hence people weren’t prepared to rescue themselves,’ Jokowi’s office said in a statement. Generally, a tsunami will come after an earthquake, but this time, ‘it came without being preceded by a quake.’

The tsunami hit Tanjung Lesung, a surfing haven in the western-most part of the Java island that’s been branded a new Bali by Jokowi’s administration. Three to four hours from capital Jakarta, Tanjung Lesung shares its coastline with Ujung Kulon National Park, and is located near factories of state-owned steelmaker PT Krakatau Steel and PT Chandra Asri Petrochemical.

Twenty nine people, mostly employees of state-run electricity producer PT Perusahaan Listrik Negara, were killed when the tsunami wave swept away the venue of a live music concert attended by about 200 people in Tanjung Lesung. The company said 13 people were still missing while 157 survived.

No significant damage was reported by companies with major factories nearby. Lampung’s Panjang Port, the main gate for robusta coffee exports, is operating normally, according to Qudratul Ikhwan, head of the provincial transportation office. Indonesia is the world’s third-biggest robusta producer.

Indonesia’s 17,000 islands are prone to earthquakes because the country straddles the Pacific Ring of Fire, an arc of fault lines and volcanoes that causes frequent seismic upheavals. Mount Krakatau is about 156 kilometers of west Jakarta and its eruption in 1883 was one of the deadliest volcanic eruptions in the world, killing more than 36,000 people.

More than 2,000 people were killed and about 80,000 people displaced in Central Sulawesi in September after a devastating earthquake and tsunami struck the island. That was preceded by a series of deadly earthquakes early this year that rattled the popular tourist destination of Lombok island, near Bali.