Police on Thursday questioned seven Chinese activists who landed on disputed territory in the East China Sea the previous day and plan to hand them over to prosecutors for allegedly violating immigration laws.

Investigators could have turned the activists over to immigration authorities before sending them to prosecutors, but police sources said this option was rejected due to the serious nature of the incident. The seven will be handed over to prosecutors Friday afternoon, they said.

The incident was rapidly turning volatile, with diplomats in Tokyo and Beijing criticizing each others' actions.