(CNN) More deadly tsunamis could strike the Indonesian coastline in the coming days, authorities warn, as the volcano which triggered the weekend's devastating wave continues to erupt.

At least 373 people have died from the tsunami, which struck the Indonesian coastline without warning Saturday night. Hundreds more are injured and more than two dozen remain missing.

In the wake of Saturday's disaster, Indonesian President Joko Widodo ordered Indonesia's Meteorology, Climatology and Geological Agency (BMKG) to purchase detectors which would provide "early warnings to community."

Eyewitnesses described fleeing for their lives as beachfront homes were swept away in the wave, which is thought to have been caused by underwater landslides following the eruption of the Anak Krakatau volcano.

According to local media, the wave reached as high as three meters (10 feet).

Sutopo Purwo Nugroho, a spokesman at Indonesia's National Disaster Mitigation Agency, warned Sunday that more tsunamis were possible as long as the volcano remained active.

"We are cautioning the people to remain cautious," Sutopo said. "Agencies are still continuing to analyze the root cause ... the Krakatau volcano continues to erupt, which could potentially trigger another tsunami."

Adding weight to his warnings, Sutopo raised the issue of Indonesia's outdated tsunami buoy network which he said hasn't worked properly since 2012.

"Vandalism, limited budget, technical damage caused no tsunami (alerts) at this time," he said on his official Twitter account.

A lack of warning was also blamed for the high death toll in Indonesia's October tsunami which killed more than 2,000 people on the western coast of Sulawesi.

Taken by surprise

A crowd was watching Indonesian pop band Seventeen at a show organized by state-run electric company PLN at the Tanjung Lesun beach resort when the massive wave crashed through the stage and threw it into the audience.

In a series of emotional messages posted on Instagram, lead singer Riefian Fajarsyah said that his three band members and Seventeen's manager, had died.

Fajarsyah's wife, Dylan, is still missing.

"I am still here - I am not going anywhere - I will pick you and we can come home together sweet heart," Fajarsyah said.

According to Indonesia's National Disaster Mitigation Agency, 1,459 people were injured and 128 people are missing. Another 5,665 people have been displaced.

Daniel von Rège, head of mission in Indonesia for Doctors without Borders, said more bodies and injured people were expected to arrive at hospitals across the region over the coming days.

At least 558 houses were destroyed, while nine hotels, 60 restaurants and 350 boats were heavily damaged, an indication of the tsunami's impact on residential and tourist areas.

No foreigners had been reported killed or injured.

Indonesian President Joko Widodo headed to the disaster zone on Monday morning, saying on his official Twitter he was praying for the victims of the tsunami.

Tsunami caused by underwater landslides

Indonesia's Ministry of Maritime Affairs confirmed on Monday that the tsunami had been triggered when the Anak Krakatau volcano erupted in the Sunda Strait between the islands of Java and Sumatra, prompting a series of underwater landslides.

"Sixty-four hectares of the slope collapsed ... Our censors did not sound early warning because they are for tectonic activity not volcanic activity," spokesman Rahmat Djamaluddin said.

When the displaced rock shifted beneath the water's surface, it "pushed up" the water on top of it, CNN meteorologist Allison Chinchar said, and generated the tsunami.

JUST WATCHED How the tsunami occurred without warning Replay More Videos ... MUST WATCH How the tsunami occurred without warning 02:13

Anak Krakatau sits between the islands of Java and Sumatra.

The tsunami's impacts were compounded by a tidal wave caused by the full moon, BMKG said in a news release.

Anak Krakatau is known for its 1883 eruption -- one of the deadliest in recorded history -- that killed more than 36,000 people.

Despite the devastating 2004 Boxing Day tsunami that killed hundreds of thousands of people, Indonesia lacks proper equipment to warn of an incoming tsunami threat.

Photos: In pictures: Latest tsunami hits Indonesia beaches An Indonesian soldier looks at damaged houses and debris in Sumur, Indonesia, on Tuesday, December 25. Hide Caption 1 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A woman holding an umbrella walks in the rain among debris after the tsunami in Sumur on Wednesday, December 26. Hide Caption 2 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Members of an Indonesian search and rescue team carry an elderly woman on a stretcher at the ferry port after being evacuated from Sebesi Island, in Bakauheni, on Wednesday. Hide Caption 3 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A tsunami survivor walks around Sumur on Tuesday. Hide Caption 4 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches An aerial view of an affected area of Sumur. Hide Caption 5 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches People clean up a mosque. Hide Caption 6 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A man reacts after identifying a relative during a rescue operation at a beach front hotel in Pandeglang on Monday, December 24. Hide Caption 7 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Villagers walk through debris in Carita, Banten province, Indonesia, on Monday following the tsunami. Hide Caption 8 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A survivor sits on debris as she salvages items from her destroyed house in Sumur, Indonesia. Hide Caption 9 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A man stands on debris from a house in Carita, Banten province. Hide Caption 10 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Debris covers a promontory at the Villa Stephanie holiday resort in Carita. Hide Caption 11 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Tsunami survivors rest at a hospital in Pandeglang, Indonesia, Monday. Doctors are working to help survivors, and rescuers are looking for more victims from a deadly tsunami that smashed into beachside buildings along an Indonesian strait. Hide Caption 12 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Villagers search through debris after the tsunami destroyed their houses. Hide Caption 13 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Women collect rice from their destroyed houses in Carita. Hide Caption 14 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Indonesian soldiers carry the bodies of tsunami victims at a beach resort in Tanjung Lesung, Indonesia, on Monday. Hide Caption 15 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Indonesian soldiers peer into an underground space during a search for victims of the tsunami at a resort hotel Monday in Tanjung Lesung, Indonesia. Hide Caption 16 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches An aerial view of the Anak Krakatau volcano during an eruption in South Lampung, Indonesia, on Sunday, December 23. The tsunami is believed to have been triggered when the volcano, lying in the Sunda Strait between the islands of Java and Sumatra, erupted and set off a series of underwater landslides, according to Indonesia's Meteorology, Climatology and Geological Agency. Hide Caption 17 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Rescue team members carry the body of a tsunami victim in Banten, Indonesia, on Sunday. Hide Caption 18 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches An aerial photo shows damaged buildings in Carita, Indonesia, on Sunday, a day after the area was hit by the tsunami. Hide Caption 19 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Residents inspect a house damaged by the tsunami in Carita. Hide Caption 20 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Tsunami survivors gather at temporary shelter in Tanjung Lesung, Indonesia, on Sunday. Hide Caption 21 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Residents inspect a house damaged by the tsunami in Carita, Indonesia, on Sunday. Hide Caption 22 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A man breaks down after identifying his relative among the bodies of tsunami victims in Carita, Indonesia, on Sunday. Hide Caption 23 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches People search for relatives among the bodies of tsunami victims. Hide Caption 24 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A villager walks past vehicles damaged by a tsunami in Carita, Indonesia. Hide Caption 25 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A resident walks past buildings damaged by a tsunami in Carita, Indonesia, on Sunday. Hide Caption 26 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A man walks amid debris from damaged buildings in Carita, Indonesia. Hide Caption 27 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A rescuer takes part in a search for tsunami victims in Carita, Indonesia. Hide Caption 28 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Officials look through the wreckage of damaged buildings in Carita, Indonesia. Hide Caption 29 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Debris litters a property that was damaged by the tsunami in Indonesia. Hide Caption 30 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches A damaged vehicle is seen amid wreckage from buildings along Indonesia's Carita beach. Hide Caption 31 of 32 Photos: In pictures: Latest tsunami hits Indonesia beaches Residents evacuate from damaged homes. Hide Caption 32 of 32

"We need a multi-hazard early warning system," said Nugroho. "And we need lots of it."

Nugroho pointed out tsunamis are faster and less predictable than tidal waves, which are caused by atmospheric conditions.

"We used to know that a tsunami happens after an earthquake. There was no quake last night," he said, referring to the sub-aquatic landslides. "That is why there was no warning."

Prayers pour in from around the world

Pope Francis prayed for the tsunami victims at his regular Sunday Angelus service in St. Peter's Square.

"I am spiritually close to the displaced and to all the people affected, imploring God for relief in their suffering," he said. "My appeal is that these brothers and sisters may not lack our solidarity and the support of the international community."

US President Donald Trump addressed the "unthinkable devastation" on Twitter Sunday morning. "We are praying for recovery and healing," Trump wrote. "America is with you!"

Unthinkable devastation from the tsunami disaster in Indonesia. More than two hundred dead and nearly a thousand injured or unaccounted for. We are praying for recovery and healing. America is with you! — Donald J. Trump (@realDonaldTrump) December 23, 2018

The International Federation of Red Cross and Red Crescent Societies in Indonesia expects the death toll to rise, spokeswoman Kathy Mueller said. It's providing support by bringing in basic household items, clean water and equipment to clear debris.

The UN World Food Programme also stood ready to support the Indonesian government, according to WFP spokeswoman Bettina Luescher.