Tensions between the central government and Okinawa rose further on Friday as five vessels were moved into the sea near the Henoko district of Nago, in the north of the prefecture, a key step in the controversial relocation of a U.S. military base within the prefecture.

According to Defense Minister Takeshi Iwaya, five vessels, including four sand and earth barges, have been deployed to the sea near Henoko to start reclamation work on Dec 14.

By taking the step, the central government ignored a plea from the Okinawa government calling for reclamation work to be suspended at least until the prefectural government finishes an inspection into a cement company involved in the construction.