BEIJING, Jan. 23 -- Chinese air force planes have been regularly patrolling the East China Sea Air Defense Identification Zone (ADIZ) since it was established two months ago, an air force spokesman said here Thursday.

The routine patrols have beefed up China's effective control over the ADIZ, air force colonel Shen Jinke said.

On a recent patrol, multiple types of Chinese aircraft were sent to "monitor, identify, track and warn" multiple types of foreign military planes that had entered the ADIZ, Shen added.

The spokesman reaffirmed that the establishment of the ADIZ is a purely defensive move that confirms to international practices.

Normal flights by international airlines have not been affected in the zone over the past two months, Shen said.