BEIJING -- A powerful earthquake jolted China's Sichuan province Saturday near where a devastating quake struck five years ago, leaving at least 12 dead and more than 100 injured and prompting state media to warn the casualty toll could climb sharply.

The quake -- measured by China's seismological bureau at magnitude-7 and the U.S. Geological Survey at 6.6 -- struck the steep hills of Lushan county shortly after 8 a.m. toppling buildings, many of them older brick structures. People ran into the streets in their underwear and wrapped in blankets, according to photos posted online.

State-run China Central Television reported that at least 12 people were confirmed dead and more than 100 injured. Sichuan Online, the website of the official provincial newspaper, quoted a provincial earthquake bureau official it did not name as saying more than 100 people have been injured or killed.

The quake's shallow depth, less than 13 kilometres (8 miles), likely magnified the impact. The official Xinhua News Agency said that the quake rattled buildings in the provincial capital of Chengdu 115 kilometres (70 miles), to the east. It caused the shutdown of the city's airport for about an hour before reopening, state media said.

Lushan, where the quake struck, is home to 1.5 million people where the fertile Sichuan plain meets foothills that eventually rise to the Tibetan plateau. Known for its mountains, the area is near a well-known preserve for pandas.

Social media users who said they were in Lushan county posted photos of collapsed buildings and reported that water and electricity had been cut off.

A man who answered the phone at the Ya'an city government said telecommunications were cut and that medical and rescue teams are on the way to the area.

"I felt the strong quake this morning in my office. All drawers of the desk opened and some stuff on the table fell on the floor," said the man, who refused to give his name, as is usual with low-ranking Chinese government officials.

The area lies near the same Longmenshan fault where the devastating 7.9-magnitude quake struck in May 2008, leaving more than 90,000 people dead or missing and presumed dead.