The agency said there was no danger of a tsunami from the earthquake.
Masakazu Murakami, an official in charge of disaster management in Miyagi, said the quake caused no damage to utilities such as water, electricity, gas and telephone lines.
"I was in the office when the quake hit this morning. But I did not feel any tremors," Murakami said.
A police official in Miyagi said authorities there had not received any reports of damage or casualties. The official spoke on condition of anonymity, citing department policy.
Japan is one of the world's most earthquake-prone countries.
The most recent major quake in Japan killed more than 6,400 people in the western port city of Kobe in January 1995.
Experts believe Tokyo has a 90 percent chance of being hit by a major quake over the next 50 years.