Iran press/Asia: A tsunami warning was issued but lifted, according to Indonesia's disaster agency spokesman Sutopo Purwo Nugroho, Reuters reported.
The earlier quake destroyed some houses, killing one person and injuring at least 10, authorities said.
"The (second) quake was felt very strongly, we expects more damage and more victims," Nugroho said.
"We advise people to remain in safe areas, stay away from damaged buildings," Sutopo Purwo Nugroho, spokesman for the National Disaster Mitigation Agency, said in a televised interview.
He added that the national agency in Jakarta was having difficulties reaching some authorities in the area.
Terrifying video footage shows massive waves crashing into an Indonesian island as a tsunami struck after a 7.5-magnitude earthquake.
In the shocking footage, apparently recorded in Palu, Sulawesi, today, enormous waves can be seen surging forward amid terrified screams.
The water knocks down homes and smashes into trees, leaving a trail of destruction in its path, as residents cry out and try to run to safety.
The video comes as officials have confirmed a tsunami of up to two metres hit the city after a powerful earthquake rocked central Sulawesi.
Officials say waters have since receded, but families are missing.
this quake is the latest in a series of recent quakes that killed nearly 500 people on the holiday island of Lombok last month.
"The (second) quake was felt very strongly, we expects more damage and more victims," Nugroho said.
Indonesia sits on the Pacific Ring of Fire and is regularly hit by earthquakes.
In 2004, a big earthquake off the northern Indonesian island of Sumatra triggered a tsunami across the Indian Ocean, killing 226,000 people in 13 countries, including more than 120,000 Indonesia.
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