A powerful 6.9-magnitudeearthquake struck off the coast of Cebu City in the Philippines late on Tuesday, leading to power outages and damaging buildings in the region.

The United States Geological Survey pegged the depth of the quake at 10 km (6.2 miles) and recorded multiple aftershocks in the region following the earthquake, with the strongest aftershock a magnitude of 6.

Another monitoring agency said there was no tsunami threat following the quake.

Cebu City, located in the Philippines’ central Visayas region, has a population of nearly 1 million, according to the USGS.

Ian Po, police chief of Villaba in the central province of Leyte, said the quake lasted for around ten seconds. The police station building was visibly shaking from the tremor, he said.

Police Colonel Enrico Figueroa, chief of the Cebu City police, said some pole-mounted transformers exploded during the earthquake.

AFP reported later on Tuesday that the earthquake had damaged buildings and roads and knocked out power in parts of the region, with rescuers searching for possible casualties.

Reuters could not immediately verify the report.

Philippine seismology agency Phivolcs had warned of aftershocks and damage from the offshore tremor. It also warned that “strong currents and rapid changes of seawater level are expected”.

“The concerned public is advised to be on alert for unusual waves,” it said in an advisory.

Philippine lies in the Pacific “Ring of Fire,” where volcanic activity and earthquakes are common.