According to CBS News, the temblor caused the city buildings to sway prompting thousands to file out to the streets.
The U.S. Geological Survey said the earthquake hit at 7:04 a.m. (9:04 a.m. EDT; 1304 GMT) and was followed by a second quake -- of 5.1 magnitude -- eight minutes later.
Both tremors set off hundreds of alarms and caused fear on the streets of Mexico's capital as many people rushed to evacuate tall buildings.
As of now, there have been no reports of damages or injuries.
CBS points out that Mexico City's soft soil makes it especially susceptible to nearby earth movements, which would explain why the city shook the morning after its neighbor Guatemala -- more than 750 miles away -- was struck by a 6.2 magnitude earthquake Monday night.