A tsunami triggered by a powerful 7.5 magnitude earthquake off the coast of the Indonesian island of Sulawesi on Friday evening crashed into least two cities, including the popular tourist resort of Palu, killing almost 400 people dead and injuring some 540 others. 

The tsunami, up to 2 meters high, swept away houses in Palu, the capital of central Sulawesi province. It also struck a smaller city, Donggala, closer to the epicenter of the quake 80 kilometers (50 miles) away.

National Disaster Mitigation Agency put the official death toll at 384 based on hospital reports, almost all them in the hard-hit city of Palu.

The death toll continues to rise as rescuers retrieve bodies in the bestricken city of Palu

"When the (tsunami) threat arose yesterday, people were still doing their activities on the beach and did not immediately run and they became victims," agency spokesman Sutopo Purwo Nugroho said on Saturday.

Communications in the area have been cut due to power outages, hampering rescue and clean-up efforts. The city's airport was also closed after its runway and a control tower were damaged in the quake. Officials said they were rushing to reopen the airport to allow aid to come in.

A smartphone video circulating on the social media showed a powerful wave hitting Palu with people screaming and fleeing in panic. The wave damaged several buildings, including a mosque.

Indonesia geophysics agency says Sulawesi quake caused a tsunami. This video is doing the rounds. We believe it is real. pic.twitter.com/7xDzzRuj5v

David Lipson (@davidlipson) September 28, 2018

Indonesian president Joko Widodo said the military had been called in to the disaster-struck region to help search-and-rescue teams reach victims and retrieve bodies.

Nugroho described the damage as "extensive," adding that thousands of houses, hospitals, shopping malls and hotels had collapsed, while a bridge had also been washed away.