The tsunami death toll in Indonesia nearly doubled to 429 on Tuesday — as fears about additional massive waves sent hundreds of traumatized residents fleeing to higher ground.

Panicked locals in Sumber Jaya on the island of Java fled their village — sobbing and clutching children — as a false alarm spread that another tsunami was about to smash into the shattered community.

“Water is coming! Water is coming!” people screamed as they ran inland while reciting verses from the Koran and emergency messages blared over local mosque speakers.

A similar frenzy over another false alarm broke out in the tsunami-stricken area of Tanjung Lesung Beach, a couple of hours away on the island. The rising water turned out to be just a regular tidal surge.

Still, a high-tide warning is in effect for the region until Wednesday.

Unlike other tsunamis that have hit the disaster-prone multi-island nation after big earthquakes, Saturday’s large waves struck without warning, devastating communities on the shores of the Sunda Strait.

The powerful surge uprooted concrete buildings and ripped out trees while killing hundreds, injuring at least 1,400 and leaving more than 16,000 people displaced. At least 128 people are still missing.

Indonesia has an advance-warning system for earthquakes, but this disaster wasn’t caused by a quake.

Instead, an underwater landslide spurred by eruptions of the nearby Anak Krakatau volcano is believed to have sent huge waves crashing into Java and Sumatra Saturday night.

Indonesia has a network of tsunami-detecting buoys off the coasts that can send big-wave warnings to the national disaster agency — but they have been broken since 2012, an agency spokesman admitted.

On Tuesday, officials said the installation of new buoys capable of detecting tsunamis caused by undersea landslides is set to start in 2019.

But experts say even if the buoys had been working, the warning time would have been minimal given how close the volcano is to shore.

With Post wires