TOKYO (AP) — A powerful earthquake struck off Japan's northern coast on Thursday, but the country's meteorological agency said there was no danger of a tsunami.

The quake had a preliminary magnitude of 6.9 and occurred off the eastern coast of Iwate, the Japan Meteorological Agency said. The quake had a depth of about 50 kilometers (30 miles), it said. The U.S. Geological Survey also reported a magnitude of 6.9.

The rattling occurred in the area where strong earthquakes have repeatedly been reported in recent months, including one that triggered a weeklong mega-quake caution advisory in December.

The quake, which struck Japan's northeastern region during Thursday's morning rush hour, also mildly shook Tokyo. There were no immediate reports of injuries or damage, according to top government spokesperson Minoru Kihara.

Prime Minister Sanae Takaichi told reporters in Tokyo that her government's emergency team is "putting people's lives first," while assessing information and preparing for relief operations, if needed. She urged residents in the affected regions to use caution against possible aftershocks.

Tomoko Nagane, a primary school principal in the town of Hashikami in Aomori prefecture, told NHK that she was driving when the quake alert went off and that she felt moderate sideway shaking. Children already gathered at the school were safe, she said, though some were crying in fear. Classes were canceled for the day and children have all returned home safely, Nagane said.

READ MORE: Back-to-back powerful earthquakes slam Venezuela, collapsing buildings in the capital of Caracas

Footage on Japan's NHK public television quoted its journalists from a number of strongly-hit towns, including Sendai and Morioka, saying they felt the shaking for a couple of minutes but have not seen any damage. Footage showed people commuting as usual.

The East Japan Railway Co., which operates trains in northeastern regions, said some bullet trains and other local lines have been suspended for safety checks.

Nuclear power plants and facilities, including the Fukushima Daiichi plant which was damaged by the 2011 massive quake and tsunami, and a spent fuel reprocessing plant in Aomori, have not reported any abnormalities from Thursday's earthquake, Kihara said.

Japan, which sits on the structure known as the Pacific Ring of Fire, is one of the world's most earthquake-prone areas.