The Japanese government says six Chinese surveillance ships have entered Japanese waters near disputed islands in the East China Sea.

In response, the Japanese government mobilized a task force at the crisis management center at the prime minister's office Friday morning, said Hikariko Ono, spokeswoman for the prime minister's office.

Ono says that after warnings from Japanese coast guard ships, two or three of the Chinese ships apparently left Japanese waters Friday morning, but the others remain.

The Chinese Foreign Ministry confirmed that six surveillance ships had entered waters near the islands, which China also claims.

It was the first intrusion by Chinese vessels into Japanese waters since Japan bought the islands from their private Japanese owners this week. The islands are called Senkaku by Japan and Diaoyu by China.