XINING, China — Soldiers and civilians used shovels and their bare hands to dig through collapsed buildings in search of survivors after strong earthquakes struck a mountainous Tibetan region of China on Wednesday, killing at least 589 people and injuring more than 10,000.

The series of quakes flattened buildings across remote western Yushu county and sent survivors, many bleeding from their wounds, flooding into the streets of Jiegu township. State television showed block after devastated block of toppled mud and wood homes. Local officials said 85 percent of the structures had been destroyed.

Residents and troops garrisoned in the town used shovels and their hands to pull survivors and bodies from the rubble much of the day. Several schools collapsed, with the state news agency saying at least 56 students died. Worst hit was the Yushu Vocational School, where Xinhua cited a local education official as saying 22 students died.

Footage on Qinghai Satellite TV showed bodies wrapped in blankets lying on the ground while rescuers pulled shards of concrete from a pancaked school building.

Crews set up emergency generators to restore operations at Yushu’s airport, and by late afternoon the first of six flights landed carrying rescue workers and equipment. But the road to town was blocked by a landslide, hampering the rescue as temperatures dropped below freezing. Tens of thousands of the town’s 70,000 people were without shelter, state media said.

The airport in Xining, the nearest big city some 530 miles away, was filled in the predawn hours Thursday with Chinese troops in camouflage, firefighters and rescue teams leading dozens of sniffer dogs. They were whisked onto waiting buses for the difficult drive to the quake zone, which takes 12 hours under the best of conditions.

Yang Xuesong, a rescuer from Shandong province in eastern China, said his biggest concern was the altitude. “This is the highlands. I don’t know if the search dogs can get used to it,” he said.