Voters in San Francisco, California passed a tax on sugar-sweetened beverages on Tuesday, unofficial results showed, as the push by local governments to target soda to stem obesity and diabetes gathered speed.

San Francisco Bay Area neighbor Albany, California passed a similar measure, preliminary figures showed and measures in Oakland, California and Boulder, Colorado, were on track to pass as well, with votes still being counted early on Wednesday.

The levies on sugar-sweetened beverages arrive a month after the World Health Organization recommended that governments introduce these types of taxes in a bid to battle obesity, diabetes and other diet-related diseases.

Opponents of such taxes say they hit lower income populations hardest, and that it is unfair to single out soda in the battle to fight obesity and diabetes.

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Coca-Cola Co, PepsiCo Inc and other companies in the roughly $100 billion U.S. soft drink industry are fighting the taxes at a time when soda consumption is falling.

The San Francisco measure passed 62 percent to 38 percent and the Albany measure passed 71 percent to 29 percent. With 85 percent of precincts reporting, the Oakland measure had 62 percent support to 38 percent opposed, and in Boulder the soda tax was passing 54 percent to 46 percent, with the percent of votes counted unclear.