Anti-war activists demonstrated across the nation Saturday to demand that U.S. soldiers get out of the Persian Gulf before blood is shed.

The protests, organized by diverse groups such as labor unions, veterans associations and church organizations, were held in at least 20 cities from New York to Los Angeles to Honolulu.In Washington, some 150 protesters shut down Pennsylvania Avenue to traffic in front of the White House by marching down the block and sitting in a line across the street. Police made 16 arrests.

A demonstration in Atlanta was met by flag-waving members of a soldiers' support group.

The protests came on a day lacking in unexpected military or diplomatic moves in the Persian Gulf region. In Paris, Defense Secretary Dick Cheney met with his French counterpart and said U.N. sanctions against Iraq are beginning to work and eventually will hamper Iraqi forces occupying Kuwait.

In New York City, protesters said they had 15,000 people at their rally. Police estimated the crowd at 5,000.

Marching from Columbus Circle down Broadway to Times Square, the throng took up the chant: "Hell no, we won't go; we won't fight for Texaco!"

In Washington, hundreds of tourists stopped to watch as demonstrators dumped sand, red paint and oil in a line in front of themselves to symbolize what they called the "line in the sand" that the United States should not cross.

Federal and local police blocked off the street to traffic and filled the road in front of the White House with about three dozen police vehicles before moving in. Longtime anti-war activist Daniel Ellsberg was among the protesters, but it was not immediately clear if he was among those arrested.

The protesters carried a huge banner reading, "No U.S. Troops in Middle East. No Blood." They sang, "We shall not be moved," and chanted, "End the occupation, with self-determination."

A handful of counter-demonstrators plaintively sang "America the Beautiful" on the nearby sidewalk, and carried signs reading, "Nuke Iraq."

In San Francisco, about 1,500 people gathered for their rally against the U.S. presence in the Middle East, police said.