TOKYO: Japan paused on Friday to mark five years since an offshore earthquake spawned a monster tsunami that left about 18,500 people dead or missing along its northeastern coast and sparked the worst nuclear disaster in a quarter century.

Emperor Akihito, Empress Michiko, Prime Minister Shinzo Abe and other participants at a national ceremony in Tokyo bowed their heads along with residents across the affected region at 2:46 pm (0546 GMT), the exact moment on March 11, 2011 the magnitude 9.0 quake struck under the Pacific Ocean.

The massive earthquake unleashed a giant wall of water that swallowed schools and entire neighborhoods, with unforgettable images of panicked residents fleeing to higher ground and vehicles and ships bobbing in the swirling waters of flooded towns.

The waves also swamped power supplies at the Fukushima Daiichi plant, causing reactor meltdowns that released radiation in the most dangerous nuclear disaster since Chernobyl in 1986.

In the northern city of Sendai in Miyagi prefecture — the region that suffered the most deaths — survivors and bereaved relatives gathered at a Buddhist statue built for the repose of victims’ souls in front of a huge breakwater at Arahama beach where massive waves crashed ashore five years ago. Some joined hands in prayer, while a woman threw a bouquet of flowers into the sea.

Police and firefighters were seen combing beaches along the Pacific coast in continuing efforts to find evidence of victims, including bones, as many families say they still cannot abandon hope of seeing their loved ones again.

In remarks at the solemn event in Tokyo inside the National Theater, 82-year-old Akihito spoke of those who were forced to evacuate after the disaster because of nuclear contamination. “I feel pain in my heart when I think of people who still could not return home,” he said.

The crisis forced tens of thousands of residents near the stricken plant to flee their homes, farms and fishing boats. Some areas remain uninhabitable, though in others residents have been cleared to return.