The agency said the waves struck at least two locations in the province, namely Mamuju and the provincial capital of Palu.

“According to our tide gauge in Mamuju, a rise in the sea level of 6 centimeters was recorded in the city at 5:27 p.m. Jakarta time. Meanwhile, witnesses in the field saw a 1.5-meter rise in the sea level in Palu,” Dwikorita said during a press briefing on Friday.

She claimed the height of the waves decreased gradually, prompting the agency to end the tsunami warning status at 5:36 p.m.

The agency confirmed a tsunami had struck the province hours after videos of what appeared to be a tsunami hitting Palu Grand Mall and Baiturrahman Mosque had been circulating online.

Critics have questioned why the agency decided to revoke the warning when a tsunami did take place.

The BMKG issued a tsunami warning for the western and central part of Sulawesi at 5:07 p.m. The warning, however, was revoked around 30 minutes later.

According to the National Disaster Mitigation Agency (BNPB), the BMKG had initially given a different reason for revoking the warning.

“The decision was based on visual monitoring and further monitoring using the equipment [tsunami detection buoys] at the sea for 30 minutes. The BMKG did not see any significant change in the sea level. That’s why they ended the alert,” BNPB spokesman Sutopo Purwo Nugroho said in a statement. 

The 7.7-magnitude earthquake hit Donggala regency, around 73 kilometers from Palu, at 5:02 p.m. Jakarta time. Sutopo said in a written statement that the epicenter of the quake was located about 27 km north-east of Donggala at a depth of 10 km.