TOKYO: A powerful magnitude 5.9 earthquake shook the Tokyo area on Thursday night, injuring at least 17 people and halting trains and subways.
Officials said there was no major damage or danger of a tsunami.
The Meteorological Agency said the quake was centred in Chiba prefecture, just east of Tokyo, at a depth of 80 km (48 miles).
It caused buildings to sway and hanging objects such as signs to swing violently.
Chief Cabinet Secretary Hirokazu Matsuno said there were no abnormalities at nuclear power facilities in the area.
He said a total of 17 people were injured, including one who was seriously hurt.
He did not describe the injuries of the others, but Chiba prefectural police said two women in separate locations sprained their ankles when they were thrown to the floor during the quake.
NHK public television said a commuter train partially derailed when it made an emergency stop, causing three passengers to fall and get slightly injured.
Others were injured in Kanagawa prefecture, near Tokyo, according to media reports.
Tokyo Electric Power Company Holdings said about 250 homes in downtown Tokyo temporarily lost power.
Shinkansen super express trains in and out of Tokyo were halted for safety checks but later resumed operation, East Japan Railway Co said.
Tokyo's Yamanote loop line and subways also restarted.
Outside of Tokyo's Shinagawa station, where local trains were temporarily halted, there was a long line of people trying to get taxis home.
Many elevators automatically stopped, including those at Tokyo's metropolitan government building, temporarily trapping some people.
Fire and disaster officials said underground water pipes were damaged in dozens of locations in Tokyo.
In one district, water was gushing from the ground.
New Prime Minister Fumio Kishida posted a message on Twitter urging people to check the latest information and take action to protect your lives.
He said it was the strongest shaking in Tokyo since March 2011.
Kishida returned to his office late Thursday to lead the government's response.