According to the U.S. Geological Survey, the quake, centered about 38 miles north-northwest of San Antonio, Puerto Rico, struck at 11:23 p.m. Monday. Several aftershocks, ranging in magnitude from 2.5 to 5.1, followed, the agency said.
The National Weather Service said the temblor did not pose a tsunami risk to Puerto Rico, a U.S. territory. So far, emergency management officials have not received any reports of injuries or significant damage associated with the earthquake, The Associated Press reported.
Meanwhile, Puerto Rico Gov. Wanda Vazquez took to social media to urge residents "to remain calm during these natural events to guarantee safety."
Others shared videos and photos in the quake's aftermath.
According to the AP, officials previously decided to close government buildings and schools as Karen approached. The storm was expected to bring heavy wind and rain to Puerto Rico on Tuesday, the National Hurricane Center said in an overnight advisory.
– The Associated Press contributed to this report.