WASHINGTON - 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 public safety and justice. He says on Twitter that organizers of the march are increasing the turnout estimate to half a million.

There were early signs across Washington that Saturday's crowds could top those that gathered on Friday to watch President Donald Trump's inauguration.

Metro subway stations and train cars are full in many locations, while ridership on Friday was well off the numbers from Barack Obama's first inaugural.

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.

Hillary Clinton is praising those attending the Women's March on Washington.

The former Democratic nominee for president is thanking attendees on Twitter for "standing, speaking and marching for our values." She says it's as "important as ever."

Clinton is also reviving her campaign slogan and says in the tweet she believes "we're always Stronger Together."

Clinton's show of support for the march comes a day after she attended President Donald Trump's inauguration at the U.S. Capitol.