Update: SENDAI, Japan (AP) - A tsunami warning issued after a magnitude-7.1 aftershock rattled Japan has been lifted.
The warning was in place for only about an hour. The aftershock shook buildings and briefly forced Tokyo's main international airport to close both of its runways, but there have been no immediate reports of damage or injuries.
The warning came as Japan observes the one-month anniversary of the massive wave that killed as many as 25,000 people.
The epicenter of Monday's aftershock was just inland and about 100 miles (160 kilometers) north of Tokyo.
The operator of the crippled Fukushima Dai-ichi nuclear complex says the latest quake briefly cut power but it was quickly restored. Operations there are not endangered.
SENDAI, Japan (AP) - A magnitude-7.1 aftershock has rattled Japan on the one-month anniversary of a massive earthquake that spawned a deadly tsunami.
A warning has been issued for a 3-foot (1-meter) tsunami, the same as after another 7.1 aftershock that shook the northeast coast last week. There was no tsunami after that quake.
People at a large electronics store in central Sendai screamed and ran outside, though the shaking made it hard to move around. Mothers grabbed their children, and windows shook. After a minute or two, people returned to the store.