People attend a Christmas service at Rahmat Pentecostal Church in Carita, Indonesia, Tuesday, Dec. 25, 2018 Image Credit: AP

Carita, Indonesia — A small Christmas service was held near a stretch of Indonesia’s tsunami-struck coastline on Tuesday, as panicked residents in one coastal town tried to flee after rumours spread that another deadly wave was about to smash into the coast.

It turned out to be a false alarm, but widespread fears about a repeat disaster — and warnings that clean water and medicine supplies were running low — rippled across the region as the death toll from Saturday’s volcano-triggered disaster topped 400.

Thousands more have been displaced, with many left homeless after houses were flattened by the killer wave.

“A lot of the children are sick with fevers, headaches and they haven’t had enough water,” said Rizal Alimin, a doctor working for NGO Aksi Cepat Tanggap, at a local school that was turned into a temporary shelter.

“We have less medicine than usual ... It’s not healthy here for evacuees.”

The powerful tsunami struck at night and without warning, sweeping over popular beaches on southern Sumatra and the western edge of Java and inundating tourist hotels and coastal settlements.

The latest death toll stood at 429, with 1,485 people injured and another 154 still missing.

Indonesia is a Muslim majority nation but has a Christian minority, with services held on Tuesday to celebrate Christmas — and pray for those affected by the deadly tsunami.

Dozens attended a sombre service at the Rahmat Carita Pentecostal church near one of the worst-hit areas.

“This Christmas is different because we’re celebrating it during a disaster,” said congregant Eliza.

“For me, it’s a chance to contemplate.”

Experts have warned that more deadly waves could slam the stricken region now covered by mountains of overturned cars, boats, furniture and other debris.

Many evacuees are too afraid to go home.

“I’ve been here three days,” said Neng Sumarni, 40, who was sleeping with her three children and husband on the school’s floor with some three dozen others.

“I’m scared because my home is right near the beach.”

Authorities are using sniffer dogs to try to find any survivors and victims’ bodies, while they have turned to drones to survey the devastated coastlines.

Abu Salim, with volunteer disaster aid group Tagana, said aid workers were scrambling to stabilise the situation by setting up public kitchens and tents for shelter.

“[People] still don’t have access to running water,” he said.

“There are many evacuees who fled to higher ground and we still can’t reach them.”