Organizers expected up to 30,000 Iraq war protesters to descend upon Washington, D.C., Saturday, three days ahead of the four-year anniversary of the U.S.-led invasion of Iraq and a day after more than 200 protesters were arrested outside the White House.

Anti-war activists were planning to march from the Vietnam Veterans Memorial across to the Potomic River to the Pentagon; smaller demonstrations are planned in cities across the country.

Thousands of Christians prayed for peace at an anti-war service Friday night at the Washington National Cathedral, kicking off a weekend of protests around the country to mark the fourth anniversary of the war in Iraq.

Afterward, participants marched with battery-operated faux candles through snow and wind toward the White House, where police began arresting protesters shortly before midnight. Protest guidelines require demonstrators to continue moving while on the White House sidewalk.

"We gave them three warnings, and they broke the guidelines," said Lt. Scott Fear. "There's an area on the White House sidewalk where you have to keep moving."

About 100 people crossed the street from Lafayette Park — where thousands of protesters were gathered — to demonstrate on the White House sidewalk late Friday. Police began cuffing them and putting them on buses to be taken for processing.

Fear said 222 people had been arrested by Saturday morning. The first 100 were charged with disobeying a lawful order, and the others with crossing a police line. All of them were fined $100.

The windows of the executive mansion were dark, as the president was away for the weekend at Camp David in Maryland.

John Pattison, 29, said he and his wife flew in from Portland, Ore., to attend his first anti-war rally. He said his opposition to the war had developed over time.

"Quite literally on the night that shock and awe commenced, my friend and I toasted the military might of the United States," Pattison said. "We were quite proud and thought we were doing the right thing."

He said the way the war had progressed and U.S. foreign policy since then had forced him to question his beliefs.

"A lot of the rhetoric that we hear coming from Christians has been dominated by the religious right and has been strong advocacy for the war," Pattison said. "That's just not the way I read my Gospel."

The ecumenical coalition that organized the event, Christian Peace Witness for Iraq, distributed 3,200 tickets for the service in the cathedral, with two smaller churches hosting overflow crowds. The cathedral appeared to be packed, although sleet and snow prevented some from attending.

"This war, from a Christian point of view, is morally wrong — and was from the beginning," the Rev. Jim Wallis, founder of Sojourners/Call to Renewal, one of the event's sponsors, said toward the end of the service to cheers and applause. "This war is ... an offense against God."

In his speech, the Rev. Raphael G. Warnock, senior pastor at Atlanta's Ebenezer Baptist Church, lashed out at Congress for being "too morally inept to intervene" to stop the war, but even more harshly against President Bush.

"Mr. Bush, my Christian brother, we do need a surge in troops. We need a surge in the nonviolent army of the Lord," he said. "We need a surge in conscience and a surge in activism and a surge in truth-telling."

Celeste Zappala of Philadelphia recounted how she learned of the death of her son, Sgt. Sherwood Baker, who served in the National Guard. When a uniformed man came to her door asking if she was Baker's mother, she said yes.

"'Yes,' and then I fell to the ground and somewhere outside of myself I heard someone screaming and screaming," she said.

The Friday night events mark the beginning of what is planned as a weekend of protests ahead of Tuesday's anniversary of the U.S.-led invasion, which began on March 20, 2003.