WASHINGTON (AP) - Pope Benedict's first public Mass in the United States is under way in Washington, where tens of thousands of people have turned out to hear the pontiff.

The stadium is filled to capacity. Many in the crowd waved to Benedict as he stood in the back of a white popemobile, making its way around the field at Washington's brand-new baseball stadium.

More than four hours before the Mass, it was standing-room only on subways. Vendors hawked Vatican flags and souvenir buttons, but there were few takers as people hurried toward the stadium.

Later today, Benedict is scheduled to address Catholic educators and meet with leaders of other faiths.

(Copyright 2008 by The Associated Press. All Rights Reserved.)

AP-NY-04-17-08 1028EDT