Associated Press An unidentified injured woman lays on the street as a man tends to her yesterday in Taipei. The woman was driving when a construction crane fell onto her car from a high-rise building during a 6.8-magnitude earthquake.

TAIPEI, Taiwan - Cranes and scaffolding at a high-rise building site went crashing to the ground after a powerful earthquake jolted Taiwan yesterday, killing four construction workers, authorities said.

More than 200 injuries were reported across the island, mostly minor, as the quake started fires, shattered windows and cracked walls. Local officials said it registered magnitude 6.8, but the U.S. Geological Survey estimated it higher, at 7.1.

Two cranes fell from the 60th floor of a high-rise building under construction. Television footage showed the cranes tumbling down from the top of the structure, bringing steel beams and chunks of cement down with them.

Police identified the victims as two crane operators and two other construction workers. Dozens of other workers, many of them from Thailand, ran down from the structure safely, witnesses said.

One crane brought down large chunks of scaffolding, witnesses said. The second crane fell down the other side of the building and smashed several cars, they said.

About 10 people were hurt by the falling debris, including a woman whose hand was severed when part of a crane came crashing down on her car.

"I pulled over my car and ran for a few steps before I saw a falling steel beam smashing another car, right in front of me," taxi driver Wang Tien-tse told the TVBS television station.

The building under construction, the Taipei Financial Center, will be Taipei's tallest when completed, towering more than 100 stories high.

Elsewhere in Taipei, the capital, buildings rocked back and forth, cracks appeared in walls and frightened people ran from homes and churches. State radio said that gas leaks started several small fires.

An old four-story building in downtown Taipei partially collapsed and was tilting toward the street. Rescue workers pulled seven people, including three children, from the structure and no others were believed trapped inside.

Wang Mei-man was on the third floor of her brothers' office in downtown Taipei when the quake struck. The entire room shook, including tables and other heavy furniture.

"I was scared to death," she said.

The government's Disaster Control Center said that some 220 people were injured across the island, but most of the injuries were minor.

Landslides along the island's east coast disrupted highway traffic, and Taipei's subway system was closed for four hours for damage inspection. Flights continued as scheduled from Taiwan's two international airports, however.

The Central Weather Bureau said that the quake was centered off the coastal city of Hualien, 108 miles east of Taipei, the island's capital. It struck at 2:53 p.m. and lasted nearly a minute, the bureau said.

Seismologists said that the quake was relatively shallow compared with most that hit Taiwan. It was felt throughout the island and was centered about six miles below the ocean floor.

More than 100 aftershocks were registered, including one with a magnitude of 4.7.

Authorities in Japan warned inhabitants of its southernmost island chain to be on the alert for tsunami waves that can be generated by seismic activity. Small tsunami waves of up to 8 inches reached Yonaguni, the closest island in the chain to Taiwan, but the alerts were later lifted.

Tremors frequently shake Taiwan, but most cause little or no damage. However, a magnitude 7.6 earthquake in September 1999 killed 2,378 people and destroyed more than 40,000 homes.