The U.S. Geological Survey said the magnitude-5.8 earthquake struck at 1:16 a.m. (0516 GMT) Sunday about four miles (six kilometers) from the small community of Espino on the western side of the U.S. Caribbean island and 63 miles (101 kilometers) from the capital, San Juan, where it was felt by high-rise dwellers.
It was recorded at a depth of 67 miles (113 kilometers), according to the USGS.
The quake cracked the concrete foundations of a few buildings in the towns of Florida, Lares, Moca, Utuado and Vega Baja, according to Puerto Rico's emergency management agency.
Agency spokeswoman Melina Simeonides said the quake also spilled rocks over a highway in Utuado, where it also shifted a concrete house some four inches from its foundation.
Engineers were trying determine if other damaged homes were safe.
Local authorities on Sunday were monitoring coastal areas close to the epicenter and evaluating the damage.
