KEELUNG, Taiwan >> China conducted “precision missile strikes” Thursday in waters off Taiwan’s coasts as part of military exercises that have raised tensions in the region to their highest level in decades following a visit by House Speaker Nancy Pelosi.

China earlier announced that military exercises by its navy, air force and other departments were underway in six zones surrounding Taiwan, which Beijing claims as its own territory to be annexed by force if necessary.

Five of the missiles fired by China landed in Japan’s Exclusive Economic Zone off Hateruma, an island far south of Japan’s main islands, Japanese Defense Minister Nobuo Kishi said. He said Japan protested the missile landings to China as “serious threats to Japan’s national security and the safety of the Japanese people.”

Japan’s Defense Ministry also speculated that four missiles flew over Taipei, the Taiwan capital city, crossing the mainland, according to a statement its embassy in Washington, D.C., posted on Twitter. Taiwan’s Defense Ministry did not deny the claim, saying that the flight path was “outside the atmosphere and is not harmful to the vast area on the ground it flies over.”

The drills were prompted by a visit to Taiwan this week by Pelosi and are intended to advertise China’s threat to attack the self-governing island republic. Along with its moves to isolate Taiwan diplomatically, China has long threatened military retaliation over moves by the island to solidify its de facto independence with the support of key allies, including the U.S.

After infuriating China over her trip to Taiwan, Pelosi met South Korean political leaders in Seoul on Thursday but avoided making direct public comments on relations with Beijing and Taipei that could further increase regional tensions.

China fired long-range explosive projectiles, the Eastern Theater Command of the People’s Liberation Army, the ruling Communist Party’s military wing, said in a statement. It also said it carried out multiple conventional missile launches in three different areas in the eastern waters off Taiwan. An accompanying graphic on state broadcaster CCTV showed those occurred in the north, east, and south.

“All missiles hit the target accurately,” the Eastern Theater said.

U.S. National Security Council spokesman John Kirby condemned the launches and military activity surrounding Taiwan.

“China has chosen to overreact and use the speaker’s visit as a pretext to increase provocative military activity in and around the Taiwan Strait,” he said Thursday. “We will not be deterred from operating in the seas and the skies of the Western Pacific consistent with international law, as we have for decades supporting Taiwan and defending a free and open Indo-Pacific.”

Taiwan’s Defense Ministry said it tracked the firing of Chinese Dongfeng series.

It said in a statement it used various early warning surveillance systems.