An earthquake with a preliminary magnitude of 6.0 rocked eastern Japan, including Tokyo, on Saturday evening, the Meteorological Agency said.
No tsunami warning was issued.
The temblor registered lower 5 on the Japanese seismic intensity scale of 7 in eastern Chiba Prefecture.
Narita airport in Chiba Prefecture temporarily closed two runways at 8:25 p.m. for checks, but landings and takeoffs were allowed to resume about 10 minutes later.
The Japan Atomic Power Co., which operates Tokai No. 2 nuclear power plant in Ibaraki Prefecture, said no abnormalities were detected at the plant due to the quake.