WASHINGTON (AP) - A city official in Washington says the turnout estimate for the Women's March on the National Mall now stands at 500,000 people. That's more than double the initial predictions.

Kevin Donahue is Washington's deputy mayor for safety and justice. He says on Twitter that organizers of the march are increasing the turnout estimate to half a million.

The march's National Park Service permit estimated a turnout of 200,000, but the District of Columbia's homeland security chief had previously predicted turnout would be higher.

Roughly 1,800 buses have registered to park in Washington on Saturday. That translates into nearly 100,000 people coming for the march just by bus.

One company has buses coming from more than 200 cities in 26 states. It's using school buses to bring people to the march from Maryland.

Many others are arriving by rail. Metro subway stations and train cars were full in many locations.

More than 600 ``sister marches'' are planned across the country and around the world.

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