Tensions between China and Japan are escalating after Chinese ships reportedly entered Japanese territorial waters near the recently nationalized Senkaku Islands.

Kyodo News and NHK said Wednesday that 12 Chinese patrol boats trespassed in waters near the islands on Tuesday alone.

The media said that Chinese and Japanese patrol boats exchanged heated verbal attacks, demanding that the other get out of their waters.

The media said ten of the Chinese boats returned late Tuesday, but two still remain in waters near the islands.

In response to the Chinese ships’ entry, the Japan Coast Guard dispatched a one-thousand-ton patrol boat that is used to seize armed vessels in addition to seven ships already in the waters.