Japanese companies have been kicked out of a major international trade fair that opened Tuesday in Sichuan Province, according to business sources in Japan.

The organizers of the Western China International Fair in the city of Chengdu sent notices to Japanese firms Monday evening asking them to pull out of the event, which runs through Sunday, the sources said.

The move is the latest in a series of retaliatory measures taken since Japan announced Sept. 11 that it nationalized three of the Senkaku islets, which China claims are part of its sovereign territory and calls Diaoyu.