Doctors treated patients in tents set up under a scorching Philippine sun on Tuesday — including helping a young mother give birth — as the death toll from a major earthquake that collapsed buildings and sparked tsunami warnings topped 40.

Thousands remained displaced and more than 450 injured following the magnitude-7.8 quake that struck off the southern island of Mindanao on Monday, according to national and local disaster agencies, though only four people were now believed missing.

In the hardest-hit Sarangani province, some areas remain accessible only by helicopter and fears of aftershocks were slowing rescue efforts, local officials told reporters at a Tuesday briefing.

“There are still aftershocks, so the rescuers are very cautious in their approach. That’s a challenge,” said regional civil defence chief Rodrigo Sosmena.

A series of powerful aftershocks rocked the area from about two hours after the first quake, while hundreds of tiny quakes followed.

Infrastructure damage, meanwhile, means some communities will be cut off for at least a week because of the damage to roads and the collapse of a bridge.

At a hospital just outside General Santos, the region’s largest city, AFP reporters heard cries of “push” then an infant’s cries as a mother gave birth outdoors behind a makeshift screen.

In Glan municipality, where at least 13 people were buried in their homes by a landslide, staff at another hospital told AFP more than 60 patients were on beds outside the facility due to fears for the building’s structural integrity.

“The hospital sustained a lot of damage,” she said.

“The municipal engineer decided we could not use the building.”

As of Tuesday morning, the death toll from provincial sources contacted by AFP stood at 41.

Deputy Prime Minister Ishaq Dar said he was “deeply saddened by the devastating earthquake in Mindanao, Philippines, which has resulted in the tragic loss of precious lives and caused widespread damage”.

Extending condolences to the bereaved families and praying for the swift recovery of the injured, Dar expressed Pakistan’s “full solidarity” with the government and the people of the Philippines.

Recovery

Outside a collapsed grocery store in General Santos, rescuers resumed efforts after an overnight break to recover two store employees who were inside when the building crumpled.

AFP journalists watched as rescue dogs and their handlers scoured the pile of broken concrete and jagged metal bars.

A local rescuer told reporters the effort was now one of recovery rather than rescue, though a more senior official later insisted that decision had yet to be formally made.

At a nearby beach resort, a high-speed Coast Guard vessel plied the waters for two people who went missing while swimming in waters that churned violently as the quake struck.

Videos posted to social media and verified by AFP on Monday showed the catastrophic collapse of a shopping centre with a Jollibee fast food restaurant in General Santos, while an unoccupied school building crumpled in another.

In another video verified by AFP, young schoolchildren could be seen screaming in the arms of their teachers as the quake violently swayed them back and forth on the ground.

A flimsy metal structure could be seen toppling in the background as the video uploaded to the school’s official Facebook page ends. An accompanying caption said no one was under the structure when it fell.

The earthquake saw thousands ordered to evacuate in coastal areas of the southern Philippines and neighbouring Indonesia as tsunami warnings were issued by multiple countries and a regional tsunami warning centre.

But by midday, the threat had passed and the alerts were cancelled.

Waves that did reach the Pacific coast of Japan, where authorities had issued a tsunami advisory, were reported to be no higher than 20 centimetres.

Eastern Mindanao was rocked by a pair of earthquakes of 7.4 and 6.7 magnitude in October that killed at least eight people.