A 6.4 magnitude earthquake rocked Puerto Rico early Tuesday morning, just one day after a 5.8 magnitude quake shook the island, according to the United States Geological Service earthquake map.
The 6.4 quake struck at 3:24 a.m. local time about 10 kilometers south of Indios, Puerto Rico USGS said. It was followed three hours later by an aftershock that measured 6.0.
The Authority of Electrical Energy, the power company for Puerto Rico, said that power plants have activated an auto protective mechanism and are out of service following the earthquake.
On Twitter, Puerto Rico Governor Wanda Vazquez Garced told citizens to remain calm as the government responds to the most recent quake.
"I hope all are well. We are getting our information from @NMEADpr and @DSPnoticias," the tweet said. "The entire government is active and in action. I ask our people to remain calm and urge you to remain safe."
No tsunami is expected following the earthquake, the US National Tsunami Warning Center said.
There were no immediate reports of damage following Tuesday's quake. The quake's magnitude was adjusted slightly downward in the hours after it struck, after initially being recorded as a 6.6.
Puerto Rico has experienced a flurry of earthquakes since December 28, according to data from the USGS, ranging in magnitude from 4.7 to Sunday's 5.8.
All of the earthquakes appear to have been foreshocks to the most recent quake, CNN Meteorologist Pedram Javaheri said.
Geologists warned that more earthquakes, known as aftershocks and tremors, would follow Monday's quake.
"When there are more earthquakes, the chance of a large earthquake is greater which means that the chance of damage is greater," the USGS said.
On Monday, the early morning quake in the same area caused some damage, including a home collapse in Guayanilla, Puerto Rico, Director of Emergency Management Carlos Acevedo said.
Acevedo also said that rock slides along Route 2 were reported.