They were the strongest aftershocks to rattle Chile since a February 27 earthquake on the country's west coast that toppled buildings and spawned a tsunami, killing several hundred people.
The first quake Thursday shook the ground near Libertador General Bernardo O'Higgins, near the Chilean coast, just as Chile prepared to inaugurate a new president, Sebastian Pinera.
The epicenter was about 95 miles (152 km) south-southwest of the capital, Santiago, and about 90 miles (145 km) away from Valparaiso, where Pinera was to be inaugurated. Television footage showed the inauguration proceeding without a hitch.
A second earthquake -- with an initial magnitude of 6.9 -- struck moments later. It was about 89 miles (143 km) southwest of Santiago, the USGS said. The third was about 86 miles (138 km) southwest of Santiago.
There were no immediate reports of damage or injuries.
Rolando Santos, senior vice president and general manager of CNN Chile, said he and his colleagues felt one of the quakes.
"I can tell you within our newsroom in Santiago, which is state of the art in terms of seismic construction, it shook for more than 45 seconds," he said.
He said that he told staffers to get under desks and that three people burst into tears. In the last two days, people had kind of gotten used to aftershocks, but "there was no question this one got everyone's attention," he said.
Pinera, a conservative billionaire businessman, became the Chilean president about 12:15 p.m. local time, roughly 20 minutes after the second quake.
The Pacific Tsunami Warning Center said in a statement that "a destructive Pacific-wide tsunami is not expected" as a result of the quakes, and that there is no tsunami threat to Hawaii.
However, the center also said that "earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within" about 62 miles (100 km) of the epicenter.
Hundreds of people were killed when the magnitude-8.8 earthquake struck Chile's west coast February 27. That quake also triggered a tsunami that toppled buildings, especially in the coastal Maule region.
Authorities this week released the names of 279 people whose bodies had been identified in the quake, but officials said the new tally does not include hundreds of unidentified victims.
The February 27 earthquake was violent enough to move the Chilean city of Concepcion at least 10 feet to the west and Santiago about 11 inches to the west-southwest, researchers said.
Breaking: Strong quake reported in Chile
[Updated 10 a.m.] Rolando Sanchez, President of CNN Chile, says the 7.2 magnitude earthquake could be felt strongly in the newsroom in Santiago, Chile.
Sanchez said the felt about four aftershocks earlier in the day, but none as intense or lasting as long as the 7.2 magnitude quake. Sanchez said some people were running and others were evacuating.
"We also have information from our crews where the inauguration is taking place that they're evacuating people around the main government building on the outside asking them to move away and move to higher ground, although the inauguration itself is continuing."
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[Updated 10 a.m.] The 7.2 magnitude earthquake shook the ground near the region of Libertador General Bernardo O'Higgins, near the Chilean coast. It struck just as Chile prepared to inaugurate a new president, Sebastian Pinera.
The epicenter was about 95 miles (152 km) south-southwest of the capital, Santiago, and about 90 miles (145 km) away from Valparasio, where Pinera was to be inaugurated. Television footage showed the inauguration proceeding without a hitch.
The quake was almost 22 miles deep and centered 95 miles southwest of Santiago, according to USGS.
The Pacific Tsunami Warning Center said in a statement that "a destructive Pacific-wide tsunami is not expected" and there is no tsunami threat to Hawaii.
[Posted at 9 a.m.] An earthquake with a preliminary magnitude of 7.2 has struck south of Santiago, Chile, the United States Geological Survey reports.
This story is currently developing. We'll bring you the latest information from Chile as soon as we get it.