A Patriot Advanced Capability-3 interceptor battery was deployed Tuesday to the Air Self-Defense Force's Aibano base in Takashima, Shiga Prefecture, the Defense Ministry said.

Aibano air base is home to a unit of the 4th Air Defense Missile Group from Gifu Prefecture. It is the seventh facility to receive a PAC-3 guided-missile fire unit.

The PAC-3 system constitutes the lower part of Japan's two-layer ballistic missile shield. It is designed to shoot down ballistic missiles in their terminal phase if the sea-launched Standard Missile-3 interceptor fails to destroy them outside the atmosphere.

PAC-3 batteries also have been deployed in Tokyo and Nagoya. Some were moved to Akita and Iwate prefectures earlier this month in case a North Korean rocket or its debris threatened to hit Japanese territory as it flew over the Tohoku region.

The ministry plans to add two more batteries to the 4th Air Defense Missile Group by the end of the summer, but none are being planned for deployment to Tohoku.