Two intense offshore earthquakes hit the same area in the southern Philippines just hours apart on Friday. The initial 7.4 magnitude quake resulted in at least six fatalities, triggered landslides, and led to the evacuation of coastal areas due to a short-lived tsunami warning.

The subsequent earthquake registered a preliminary 6.9 magnitude, which also led to a local tsunami alert. It stemmed from movement along the same fault line, the Philippine Trench, at a depth of 10 kilometers (6 miles) offshore from Manay town in Davao Oriental province, according to Teresito Bacolcol, chief of the Philippine Institute of Seismology and Volcanology.

“The second one is a separate earthquake, which we call a doublet quake,” Bacolcol informed The Associated Press. “Though they occurred in the same area, they had different strengths and epicenters.”

Bacolcol, along with other authorities, expressed concerns that the second nighttime quake might further damage or destroy structures already compromised by the first quake.

President Ferdinand Marcos Jr., dealing with this latest natural disaster following a deadly quake and consecutive storms, stated that they were assessing potential damages. Rescue teams and relief operations were being organized and would be deployed when conditions allowed.

Quake toll

Government seismologists noted that the first quake was located offshore, about 43 kilometers (27 miles) east of Manay town, originating from movement in the Philippine Trench at a depth of 23 kilometers (14 miles).

At least six people were killed, including two patients who died of heart attacks at a hospital during the first earthquake and a resident who was hit by debris in Mati city in Davao Oriental, Ednar Dayanghirang, regional director of the government’s Office of Civil Defense, told The AP.

Two villagers died and several others were rescued with injuries by army troops and civilian volunteers in a landslide set off by the first quake in a remote gold-mining village in Pantukan town in Davao de Oro province near Davao Oriental, Dayanghirang said.

Another resident died because of the first quake in the port city of Davao, disaster mitigation officials said without providing other details. They added that a few hundred residents were injured in the city.

Damage assessment

Office of Civil Defense deputy administrator Bernardo Rafaelito Alejandro IV said that several buildings sustained cracks in their walls, including an international airport in Davao city, but it remained operational without any flights being canceled.

“I was driving my car when it suddenly swayed and I saw power lines swaying wildly. People darted out of houses and buildings as the ground shook and electricity came off,” Jun Saavedra, a disaster-mitigation officer of Governor Generoso town in Davao Oriental, told The AP.

Schools evacuated

“We’ve had earthquakes in the past, but this was the strongest,” Saavedra said, adding that the intense ground swaying caused cracks in several buildings, including a high school, where about 50 students were brought to a hospital by ambulance after sustaining bruises, fainting or becoming dizzy because of the first quake.

Governor Generoso is a town about 100 kilometers (62 miles) south of Manay, where school classes in all levels were also suspended.

Children evacuated schools in Davao city, which has about 5.4 million people and is the biggest city near the epicenter, about 250 kilometers (155 miles) west of Davao Oriental province.

Tsunami fears

The Pacific Tsunami Warning Center in Honolulu said that small waves were detected on the coasts of the Philippines and Indonesia before the threat passed about two hours after the first quake. It said that small sea fluctuations may continue.

A tsunami warning that set off evacuations in six coastal provinces near Davao Oriental was later lifted without any major waves being detected, Bacolcol said.

Indonesia’s Meteorology, Climatology and Geophysics Agency said that small tsunami waves were detected in North Sulawesi province with heights ranging from 3.5 to 17 centimeters (1.3 to 6.7 inches) in Melonguane, Beo, Essang and Ganalo in Talaud Islands districts.

History of quakes and storms

The Philippines is still recovering from a Sept. 30 earthquake with a 6.9 magnitude that left at least 74 people dead and displaced thousands of people in the central province of Cebu, particularly in Bogo city and outlying towns.

The archipelago also is lashed by about 20 typhoons and storms each year, making disaster response a major task of the government and volunteer groups.

Also Friday, an earthquake with a preliminary magnitude of 6.0 struck Friday off the coast of Papua New Guinea. The U.S. Geological Survey said that it was centered in the Bismarck Sea 414 kilometers (257 miles) northeast of Lae, the South Pacific island nation’s second-most populous city.

Lae police official Mary Jane Huafilong said that no damage was reported.