TOKYO — A large earthquake shook a broad area across eastern Japan late Saturday night, with its epicenter off the coast of Fukushima, near where three nuclear reactors melted down after a quake and tsunami nearly 10 years ago.

The earthquake left nearly 1 million households without power across the Fukushima region and forced the closure of roads and suspension of train services. While rattled residents braced for aftershocks, a landslide cut off a chunk of a main artery through Fukushima prefecture.

Japan’s meteorological service reported the quake’s magnitude as 7.3, up from the initial report of 7.1, but said there was no danger of a tsunami.

Coming a little less than a month before the 10th anniversary of what is known as the Great East Japan earthquake and Fukushima nuclear disaster, the quake rattled the greater Tokyo area for about 30 seconds starting at 11:08 p.m. and was felt powerfully in Fukushima and Sendai.

The strong quake was an unnerving reminder of the 8.9-magnitude earthquake and tsunami that devastated Japan in 2011, killing 16,000 people. After the subsequent nuclear disaster in Fukushima, 160,000 people fled or were evacuated from around the plant.

The prime minister’s office immediately set up a crisis management office and the Tokyo Electric Power Co., or Tepco, which operates the nuclear plants, said it was checking its monitoring posts in Fukushima to ensure that there were no radiation leaks.

Shortly after midnight, public broadcaster NHK reported that Tepco had detected “no major abnormalities” at any of the Dai-ichi reactors where the meltdowns occurred in 2011 or at the Dai-ni plant a few miles away in Fukushima.

Speaking on NHK, Takashi Furumura, a professor at the Earthquake Research Institute at the University of Tokyo, warned that a quake of this size could be followed within two or three days by another of similar scale.