Photo/Illutration A Japan Coast Guard cutter, foreground, shadows a Chinese Coast Guard ship in waters near the disputed Senkaku Islands in the East China Sea. (Provided by Japan Coast Guard)

Chinese Coast Guard ships were spotted in the contiguous zone near the Senkaku Islands in the East China Sea on Dec. 14, marking 337 days so far this year that such sightings have been made.

The figure is also a new record and indicates Chinese ships are in the zone just outside Japanese territorial waters on an almost daily basis.

The Japan Coast Guard made the announcement. Its cutters have been on around-the-clock surveillance in the area surrounding the uninhabited islands.

Four Chinese Coast Guard ships were spotted in the contiguous zone on Dec. 14. The zone is the 12 nautical miles just outside of territorial waters.

There has been a sharp increase in the number of Chinese government ships spotted in the contiguous zone ever since the central government acquired the Senkaku Islands in Okinawa Prefecture from private ownership in 2012.

There have been only 11 days this year when Chinese ships were not sighted in the zone, due mainly to bad weather.