TOKYO -- Japan on Tuesday accused Chinese navy vessels of locking a weapons-targeting radar on a Japanese destroyer and helicopter amid escalating territorial disputes between the Asian powers.
Japanese Defense Minister Itsunori Onodera accused Chinese navy vessels of using the weapons radar in two incidents last month, on Jan. 19 and Jan. 30. He said it happened in the East China Sea, suggesting it was near disputed islands controlled by Japan but also claimed by China. He did not give an exact location.
Onodera said the action could have led to a dangerous situation. Shots were not fired on either occasion.
"It is extremely abnormal to use such fire-control radar, or radar for (weapons) firing," he told reporters in an emergency briefing. "The incident could have led to a dangerous situation in case of a misstep."
"We will sternly call on the Chinese side to refrain from such dangerous acts," he added.
The United States, which is a treaty ally of Japan, voiced concern. State Department spokeswoman Victoria Nuland said such actions could escalate tensions and increase the risk of an incident or miscalculation that would undermine peace, stability and economic growth in the region.
Chinese maritime surveillance vessels have repeatedly entered Japanese-claimed waters around the islands since last September, when Japan's government nationalized some of the islands, known as Senkaku in Japan and Diaoyu in China. The purchase triggered violent protests across China.
Japan's Foreign Ministry lodged a formal protest with China earlier Tuesday through the Chinese Embassy in Tokyo and the Japanese Embassy in Beijing, officials said. China said it would look into the alleged incidents, according to Foreign Minister Fumio Kishida.
Onodera said Japan waited to report the incidents because it took time to verify the source and nature of the radar allegedly used by the Chinese frigates.
New U.S. Secretary of State John Kerry spoke by phone Tuesday with Chinese Foreign Minister Yang Jiechi and they discussed "regional security issues," Nuland said. She declined to say whether the radar-targeting incidents were among the issues they talked about.
Associated Press writer Matthew Pennington in Washington contributed to this report.