Japan’s military was on alert for a possible North Korean ballistic missile launch, a government source said on Tuesday, with media reporting its navy and anti-missile Patriot batteries have been told to shoot down any projectile heading for Japan.

North Korea appeared to have moved an intermediate-range missile to its east coast, but there were no signs of an imminent launch, South Korea’s Yonhap News Agency reported, citing an unnamed government source.

A South Korean defense ministry official said it could not confirm the Yonhap report and said the military was watching the North’s missile activities closely.

Tension in the region has been high since isolated North Korea conducted its fourth nuclear test in January and followed that with a satellite launch and test launches of various missiles.