The Tokyo Metropolitan Assembly on Friday unanimously approved a revised ordinance banning diesel-powered commercial vehicles from the streets of Tokyo unless they meet a limit on emissions of carcinogenic particles.

The new measures, the first in Japan regulating emissions from diesel-powered vehicles, will be implemented gradually from April and take full effect in October 2003, metropolitan government officials said.

Speaking at a news conference after the session, Gov. Shintaro Ishihara said, "I think we have come up with the strictest ordinance in the nation and I would like to call on business operators and Tokyo residents to cooperate to make Tokyo's air clean again."