An explosion has occurred at a Japanese military facility inside a US air base in Okinawa, officials have said, with local media reporting non-life-threatening injuries.
The blast occurred while the JSDF personnel were preparing to carry out bomb disposal operations, Kyodo News Agency reported on Monday.
A defence ministry spokesman said they had received reports of an explosion at the Japan Self-Defense Forces (SDF) facility inside Kadena Air Base in the southern Japanese region.
Jiji Press and other local media said four injuries had been reported but none were life-threatening.
Public broadcaster NHK said, citing unnamed defence ministry sources, that the explosion may have occurred at a temporary storage site for unexploded bombs, with officials trying to confirm the situation.
"We've heard there was an explosion at the SDF facility and also heard there were injuries but we don't have further details," Yuta Matsuda, a local official of Yomitan village in Okinawa, told AFP.
No evacuation order has been issued for nearby residents, according to local officials.
Okinawa is home to the bulk of US military facilities in Japan.
China, Japan tension
Meanwhile, a Chinese aircraft carrier group entered Japan's economic waters over the weekend, before exiting to conduct drills involving fighter jets, Tokyo's defence ministry said on Monday.
The Liaoning carrier, two missile destroyers and one fast combat supply ship sailed around 300 kilometres (190 miles) southwest of Japan's easternmost island of Minamitori on Saturday, a ministry statement said.
It was the first time a Chinese aircraft carrier had entered that part of Japan’s exclusive economic zone (EEZ), a Japanese defence ministry spokesman told AFP.
"We think the Chinese military is trying to improve its operational capability and ability to conduct operations in distant areas," the spokesman said.
China's growing military clout and use of naval and air assets to press disputed territorial claims have rattled the United States and its allies in the Asia Pacific region.
Tokyo's chief cabinet secretary Yoshimasa Hayashi told reporters on Monday that the government had "conveyed an appropriate message to the Chinese side" without saying it had lodged a formal protest.
