MANILA — The death toll in a powerful 7.8‑magnitude earthquake off the southern Philippine island of Mindanao on Monday has risen to at least 32 with dozens of people injured, disaster ‌officials said, as Manila stepped up search and rescue operations.The quake, which triggered tsunami warnings across several countries, hit early in the morning about 20 km (12.4 miles) off Sarangani province, with the tremors felt strongly across Mindanao and 420 km (261 miles) away in the city of Manado on the Indonesian island of Sulawesi.Videos and images showed buildings collapsing, including a clip of a Jollibee fast food restaurant reduced to rubble, and landslides have been recorded in some areas.More than 130 people have been injured across several provinces, almost two dozen are missing, and 10,000 residents have been pre-emptively evacuated, authorities have said.Mindanao is the Philippines second-biggest island — both in size and population — and is home to around 26 million people.The Philippines mobilized military and disaster response teams and authorities were verifying preliminary reports of 32 people killed and 134 injured across Mindanao, mostly from falling debris and landslides, according to civil defence officials.Tsunami warnings were cancelled after more than six hours in the southern Philippines, northern Indonesia and the Malaysian state of Sabah on Borneo island, where residents in coastal areas had been told to evacuate immediately to higher ⁠ground.The disaster came eight months after the Philippines suffered its deadliest tremor in 12 years, opens new tab, when a shallow 6.9 magnitude quake hit off the central island of Cebu, killing 79 people. Two powerful quakes struck Mindanao two weeks later, the strongest at a magnitude 7.4.Casualty numbers still need to be verified by the national disaster agency, which tabulates and verifies reports by various local sources and is expected to provide an official update in the coming days.Local authorities in Sarangani, about 20km (12.5 miles) from the quake's epicentre, said 17 people had died there, many of them in a landslide. The quake temporarily downed power and communication networks in Sarangani though they were later restored.In General Santos, the city nearest the epicentre, 10 people were killed, the Office of Civil Defence said. Another 22 people remain missing. General Santos, known as the Philippines' tuna capital, is also known as the hometown of Manny Pacquiao, the world boxing champion who later became a politician.South Cotabato and Sultan Kudarat were also hard hit.Philippine President Ferdinand Marcos Jr said in a statement that agencies were co-ordinating their disaster response."The national government is moving and we will not leave Mindanao behind," he promised.Marcos also ordered the suspension of classes in affected areas after the quake, which coincided with the first day of the school year in the Philippines.In one video posted by a primary school in Davao Occidental province, dozens of terrified students can be seen squatting on the shaking ground.The video also showed a corrugated-roof shelter collapsing behind them, though the school said in its post that no-one had been injured.More than 130 aftershocks, with magnitudes ranging from 1.3 to 6.7, were recorded after the initial quake.Earthquakes are common in the Philippines, which sits on the geologically unstable "ring of fire". While most of these quakes are minor and pass relatively peacefully, some have proven deadly.Shortly after the quake on Monday morning, authorities in Japan warned of one-meter-tall tsunami waves reaching its shores.A tsunami wave measuring a few centimetres was later observed in the southern prefecture of Okinawa, while a 20cm (0.7ft) wave was measured in the distant Ogasawara Islands, authorities said.Waves were also detected at several locations along the coasts of Indonesia, Palau and the Philippines. The height of those waves ranged from a few centimetres to 1.4m (4.6ft), according to authorities.