Magnitude 7.5 quake in northern Japan injures 23 people and triggers a 2

TOKYO — A powerful 7.5 magnitude earthquake struck off northern Japan late Monday, injuring 23 people and triggering a tsunami in Pacific coast communities, officials said. Authorities warned of possible aftershocks and an increased risk of a megaquake.

The Japanese government was still assessing damages from the tsunami and late-evening quake, which struck at about 11:15 p.m. in the Pacific Ocean, around 80 kilometers (50 miles) off the coast of Aomori, the northernmost prefecture of Japan’s main Honshu island.

“I’ve never experienced such a big shaking,” convenience store owner Nobuo Yamada told the public broadcaster NHK in the Aomori prefecture town of Hachinohe, adding that “luckily” power lines were still operating in his area.

A tsunami of up to 70 centimeters (2 feet, 4 inches)