Five years after Washington state legalized marijuana, Seattle officials say they're moving to automatically clear past misdemeanor convictions for pot possession. San Francisco recently took the same step.

Seattle Mayor Jenny Durkan and City Attorney Pete Holmes say they want to help undo damage from the drug war they say resulted in unfairly high arrest rates for minority communities.

Several U.S. cities and states have allowed people to petition to have their pot convictions vacated or sealed.

But Seattle, San Francisco and San Diego appear to be the only major jurisdictions erasing convictions en masse.

Holmes says he expects to clear 500 to 600 convictions dating to 1997.

Seattle has long had a tolerant approach to low-level pot crimes.

Holmes hasn't prosecuted them since taking office in 2010.