JAKARTA, Indonesia — Many people are missing feared dead after a powerful earthquake rocked the Indonesian island of Sulawesi, triggering a 3-meter (10-foot) -tall tsunami that an official said swept away houses in at least two cities.

Disaster agency spokesman Sutopo Purwo Nugroho said in a TV interview that the tsunami hit Palu, the capital of central Sulawesi province, and a smaller city, Donggala.

He said houses were swept away and families were reported missing. Communications to the area were disrupted.

"The cut to telecommunications and darkness are hampering efforts to obtain information," he said. "All national potential will be deployed, and tomorrow morning we will deploy Hercules and helicopters to provide assistance in tsunami-affected areas."

Indonesian TV showed a smartphone video of a powerful wave hitting Palu with people screaming and running in fear. The water smashed into buildings and a large mosque already damaged by the quake.

The region was rocked by a magnitude 7.5 earthquake Friday and numerous strong aftershocks including one of magnitude 6.7.

The chief of the meteorology and geophysics agency, Dwikorita Karnawati, said the tsunami waves were 0.5 to 3 meters (1.6 to 10 feet) high. She said the tsunami warning triggered by the biggest quake, in place for about half an hour, was lifted after the tsunami was over.

Palu's airport halted operations for 24 hours due to earthquake damage, according to AirNav, which oversees airline traffic in Indonesia.

Mirza Arisam, a resident of Kendari, the capital of neighbouring Southeast Sulawesi, said his uncle and his family of five, including three children, were holidaying in Palu and unable to be contacted after the tsunami.

Central Sulawsi was hit earlier Friday by a magnitude 6.1 earthquake that based on preliminary information killed one person, injured 10 and damaged dozens of houses.

Television footage showed people running into the streets. Woman and children wailed hysterically in a video distributed by the disaster agency, which also released a photo showing a heavily damaged department store.

"All the things in my house were swaying and the quake left a small crack on my wall," Donggala resident Mohammad Fikri said by telephone.

Indonesia is prone to earthquakes because of its location on the "Ring of Fire," an arc of volcanoes and fault lines in the Pacific Basin.

In December 2004, a massive magnitude 9.1 earthquake off Sumatra in western Indonesia triggered a tsunami that killed 230,000 people in a dozen countries.

BREAKING: Video shows tsunami hitting the Indonesian city of Palu pic.twitter.com/XCXXHZwAtu

— BNO News (@BNONews) September 28, 2018

The Indonesian island of Sulawesi was hit with two-metre high tsunami waves. Here are the latest updateshttps://t.co/ryThFY86JR

— Daily Express (@Daily_Express) September 28, 2018

#Indonesia city of Palu hit by tsunami after earthquake, destroying houses and sweeping away residents https://t.co/WLlo3czbkt

— SCMP News (@SCMPNews) September 28, 2018

Video shows tsunami hitting Palu after 7.7-magnitude quake https://t.co/i2ztSce5kp pic.twitter.com/qvsfKZphZH

— Inquirer (@inquirerdotnet) September 28, 2018

#PrayForDonggala I heard about the earthquake and Tsunami in Indonesia, ARMYs please stay safe and everybody else who was affected, I send my prayers. 🙏 pic.twitter.com/Oysd2rJ6K6

— Hclybts (@Hclybts2) September 28, 2018

A tsunami hit the Indonesian island Sulawesi after a 7.5 earthquake, causing communications to go down and some buildings to collapse. Up to 5 people are dead, according to reports. pic.twitter.com/5tzlkxMgNK

— AJ (@ajplus) September 28, 2018

Earthquake (7.5 magnitude) & Tsunami in Sulawesi , Indonesia. I Hope all of people will be save there... #PrayforSulawesi #PrayForDonggala #BTSARMY pic.twitter.com/BMFU4Iqctp

— KSRPetite (@BTSxBelle) September 28, 2018

Officials confirm several communities have been hit by a tsunami and an unknown number of people have been killed https://t.co/xg05OhkjeB pic.twitter.com/YLeC9ZdThe

— BNO News (@BNONews) September 28, 2018

Powerful tsunami sweeps away houses in Indonesia after earthquakes shake island https://t.co/i57BgpJLvz

— TIME (@TIME) September 28, 2018

Mari sejenak kita doakan keselamatan untuk saudara-saudara kita di Palu, Sulawesi Tengah yang baru saja ditimpa musibah tsunami.
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.#PrayForPalu #PrayForDonggala #Indonesia pic.twitter.com/e3vhoxoO87

— YDBA (@YDBA_Astra) September 28, 2018