Authorities in Ibaraki Prefecture on Thursday continued to assess the damage from a strong earthquake overnight that injured two people, disrupted public transportation and caused buildings to sway in Tokyo.

Ibaraki Prefecture is home to two nuclear power plants. No immediate problems were reported at the idled Tokai No. 2 nuclear power plant, Japan Atomic Power Co. said. Tokyo Electric Power Company Holdings Inc., which runs the meltdown-hit Fukushima No. 1 plant in neighboring Fukushima Prefecture, also reported no problems.

The Ibaraki Prefectural Government said the magnitude-6.3 quake shattered windows at a junior high school gymnasium in Takahagi, where the quake registered lower 6 on the Japanese earthquake intensity scale to 7. It also caused the ceiling of an inn to collapse. Although the prefectural government said no one was injured in either case, a man in his 60s was slightly injured by a falling object in the city.

The earthquake struck near Takahagi at 9:38 p.m. Wednesday, the Meteorological Agency said. No tsunami warning was issued.

Elsewhere, a woman in her 40s sustained a minor injury when the quake caused her to fall at her home in Kitaibaraki, where rockfalls also closed a local road, authorities said.

Another man said the temblor brought back bad memories of March 11, 2011.

“I was scared because it made me recall the Great East Japan Earthquake (in March 2011),” said Kazuhiko Izumi, 59, who owns an inn in Takahagi.

Megumi Takahashi, 25, also from Takahagi, said the quake was so strong she couldn’t stay on her feet.

“I didn’t have room for bracing myself because the shaking came with a great impact,” she said.

Several people, including the elderly, voluntarily evacuated to a public shelter.

“I came here because I didn’t want to stay home alone,” one of them said.

Wider parts of the Tohoku and Kanto regions felt the quake as a 3 or 4 on the Japanese intensity scale. Buildings in central Tokyo swayed mildly for several seconds.

The quake is likely an aftershock of the magnitude-9.0 mega-quake in March 2011 that wreaked havoc on Tohoku, the weather agency said.

Public transport in Tohoku and Kanto was temporarily halted by the temblor, including the Tohoku and Tokaido shinkansen lines, which resumed shortly thereafter, East Japan Railway Co. (JR East) said.

In Tokyo, the government set up an emergency headquarters at the Prime Minister’s Office. Prime Minister Shinzo Abe, who returned home just a few hours before the quake after visiting Pearl Harbor in Hawaii, instructed relevant ministers and agencies to ascertain the extent of the damage.

At a news conference on Wednesday, Chief Cabinet Secretary Yoshihide Suga said the government will fully coordinate with municipalities in the affected areas.