China says it took lawful enforcement measures in row with Japan

China said on Thursday that it took lawful enforcement measures when it entered the waters around disputed East China Sea islets to counter what it called the incursion of Japanese vessels into Chinese territorial waters.

"That was a grave violation of Chinese sovereignty," said Chinese foreign ministry spokesperson Wang Wenbin when responding to a question on Japan's coast guard saying the Chinese coast guard vessels violated Japanese territorial waters around Senkaku Islands.