The USGS said the quake, which struck at 12:54 a.m. local time, had an epicenter about two miles (three kilometers) south-southwest of Naranjo, which is about 22 miles (35 kilometers) west of the capital San Jose. Its depth was 6.3 miles (10.1 kilometers).
A smaller earthquake shook Puerto Rico on Tuesday evening. The USGS says the magnitude 2.6 quake, which occurred at about 6:30 p.m. at a depth of 5.6 miles (nine kilometers), had an epicenter three miles (five kilometers) east-southeast of Mayaguez, or about 66 miles (106 kilometers) west of San Juan. No injuries or damage were immediately reported.