Sirens were blaring along the coastal stretch, warning residents to evacuate to higher ground, as authorities cautioned that a tsunami could be approaching. (Anna Fifield,Jason Aldag/The Washington Post)

Japan’s Fukushima region was struck by a powerful 7.4-magnitude earthquake Tuesday morning, triggering tsunami warnings and fears of another disaster in the same area that was devastated more than 5 1 / 2  years ago.

But several hours after residents along the Fukushima and Tohoku coastlines were told to evacuate to higher ground and remain there, the danger appeared to have passed, and the tsunami warnings were lifted.

The relatively shallow quake struck at 6 a.m. local time Tuesday and was centered about 15 miles off the coast from Namie, a town close to the nuclear plant. The magnitude was revised several times, but the Japan Meteorological Agency stated at 8 a.m. that it measured a 7.4. It was followed by large aftershocks measuring 5.4 and 4.8. The U.S. Geological Survey rated the earthquake at 6.9.

The agency said the quake was an aftershock of the 2011 quake and warned residents that another could strike in the next few days.

There appeared to be no damage or changes in the radiation level at the Fukushima Daiichi nuclear plant, which suffered a triple meltdown after the 2011 earthquake and remains in a highly fragile state. But Tepco, the power utility, said it was closely monitoring activity in the area, where decontamination work continues.

A cooling system at another shuttered nuclear power plant seven miles up the road shut down briefly following the earthquake, sparking fears that the fuel rods inside the reactor could heat up, but Tepco reported that normal operations had been resumed.

Bullet train services were temporarily suspended, and a fire broke out at a petrochemical plant, although it was soon extinguished.

The earthquakes were felt in Tokyo, 160 miles south of the epicenter.

Prime Minister Shinzo Abe was in Argentina on Tuesday, following the APEC meeting in Peru, but he said the government was ready to respond.

“I have ordered my government to immediately collect and provide information regarding tsunami evacuations and do everything to tackle the disaster,” he told reporters in Buenos Aires.

The enormous 9.0-magnitude earthquake that struck on March 11, 2011, caused huge damage at the Fukushima nuclear plant and the evacuation of the area around it for fear of radiation. Even today, the villages closest to the plant remain ghost towns, frozen in time.

But it was the tsunami that followed that had the most devastating results. A 50-foot-high wave inundated the Tohoku region, north of Fukushima, claiming 18,000 lives. Today, 60,000 people still live in temporary housing, and coastal towns such as Rikuzentakata remain huge construction sites, as authorities try to raise the land above the tsunami risk zone.

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Yuki Oda in Tokyo contributed to this report.