A 7.5 magnitude earthquake struck off the Indonesian island of Sulawesi on Friday, just hours after another earthquake, and caused a tsunami, Reuters reported. The tsunami hit an hour after Indonesia’s meteorology centre withdrew the early tsunami warning it had issued for the residents in Central Sulawesi and West Sulawesi provinces.

Officials reported five deaths but did not specify if they were caused by the tsunami, BBC reported. Videos on social media showed several buildings including a mosque destroyed.

Disaster agency spokesman Sutopo Purwo Nugroho told AP that disconnected power supply and telecommunications were thwarting efforts to collect information. “All national potential will be deployed, and tomorrow morning we will deploy helicopters to provide assistance in tsunami-affected areas,” Nugroho said.

An official at the agency told AP that they were still collecting information on the tsunami and would release it after checking it for accuracy.

The National Agency for Disaster Countermeasure said the tsunami hit the cities of Palu and Donggala, sweeping away houses. Some families are missing. Agency spokesperson Sutopo Purwo Nugroho added that communication systems in central Sulawesi are down, and darkness is hampering the rescue effort.

Operations at the Mutiara Sis Al Jufri Airport in Palu have been suspended, The Jakarta Post reported.

The United States Geological Survey said the earthquake was centred at a depth of 10 km about 56 km northeast of the town of Donggala, AP reported.

The first earthquake, of 6.1 magnitude, killed one person and injured 10 people. A few houses were also damaged, according to authorities.

A series of earthquakes in July and August killed nearly 500 people on the holiday island of Lombok, hundreds of kilometres southwest of Sulawesi.