Witnesses say the giant wave swept into the streets of Palu

which is on the island of Sulawesi.

Here's Rebecca Henschke in the Indonesian capital of Jakarta.

Mobile phone footage shows the terrifying moment

that up to 3-meter-high waves hit the coastal areas in the city of Palu.

And the footage shows the water sweeping into houses closest to the shore.

Other footage taken on mobile phones from ships out to sea

show the huge waves hitting the port area with people praying and screaming

you can hear in the footage.

Officials have confirmed that a tsunami has hit the area

but say casualty figures are still unclear, telecommunications to the region has been cut off

they're sending in rescue teams as we speak to reach the area

and to get the clearer picture of what's taken place here.

The quake happened around 5 p.m. local time

and was 7.7 magnitude, a significant quake for Indonesia living in the ring of fire,

a country that no stranger to earthquakes

after suffering a heavy in Lombok in July and August that killed over 500 people.

What's happened today in Palu is still to become clear.

Rebecca Henschke, BBC news, Jakarta.