JAKARTA, Indonesia — More than 100 people were killed early Wednesday and more were feared dead after a powerful earthquake struck the Indonesian island of Sumatra, with many of the victims crushed to death in their homes as they slept.

The earthquake, which shook Sumatra’s northernmost province, Aceh, had a preliminary magnitude of 6.5, according to the United States Geological Survey.

The Indonesian Meteorology, Climatology and Geophysics Agency said that the temblor, which struck after 5 a.m. at a depth of about six miles, was centered in Pidie Jaya, a region on Aceh’s east coast, adjacent to the Strait of Malacca.