NEW YORK -- Tens of thousands of antiwar protesters marched yesterday through Manhattan to demand an immediate withdrawal of US troops from Iraq just hours after an American soldier died in a roadside explosion in Baghdad -- the 70th US fighter killed in that country this month.
''End this war, bring the troops home," read one of the many signs held by protesters during the march more than three years after the war in Iraq began. The mother of a Marine killed two years ago in Iraq held a picture of her son, born in 1984 and killed 20 years later.
Cindy Sheehan, a vociferous critic of the war whose 24-year-old son also died as a soldier in Iraq, joined in the march, as did actress Susan Sarandon and the Rev. Jesse Jackson.
One group marched under the banner ''Veterans for Peace." Some marchers came from as far as Maryland and Vermont.
The demonstrators stretched for about 10 city blocks as they headed down Broadway.
A police spokesman declined to give an estimate of the size of the crowd, although organizers said there were 300,000 people. There were no arrests.
''We are here today because the war is illegal, immoral, and unethical. . . . We must bring the troops home," said the Rev. Al Sharpton.
Along with their call for the return of the troops from Iraq, organizers said, the march was meant to express opposition to any military action against Iran. The event was organized by the group United for Peace and Justice.
''We've been lied to, and they're going to lie to us again to bring us a war in Iran," said Marjori Ramos, 43, of Staten Island. ''I'm here because I had a lot of anger, and I had to do something."
Steve Rand, an English teacher from Waterbury, Vt., held a poster announcing, ''Vermont Says No to War."
''I'd like to see our troops come home," he said.
The march stepped off shortly after noon from Union Square, with the demonstrators heading to downtown Manhattan for a rally at Foley Square between the US courthouse and a federal office building.
The death toll in Iraq this month has been the highest for a single month in 2006 before yesterday's fatality. Although that figure is well below some of the bloodiest months of the Iraq conflict, it marks a sharp increase over March, when 31 American service members were killed. January's death toll stood at 62 and February's at 55. In December, 68 Americans died.
At least 2,399 members of the US military have died since the war began.
In his weekly radio address yesterday, President Bush warned Americans that there would be ''more tough fighting ahead in Iraq and more days of sacrifice and struggle."
Bush has refused to set a timetable for withdrawing the 133,000 US troops in Iraq, despite growing American disapproval of the war and of his presidency.
He said the formation of a unity government in Iraq would mark ''the beginning of a new chapter in America's involvement" in Iraq three years after a US-led invasion that toppled Saddam Hussein.
''As Iraqis continue to make progress toward a democracy that can govern itself, defend itself, and sustain itself, more of our troops can come home with the honor they have earned," Bush said.
He said the new leaders of Iraq face many challenges, including establishing security forces to defeat terrorists, rebuilding the country's infrastructure, and strengthening the economy.
The president sent Secretary of State Condoleezza Rice and Defense Secretary Donald H. Rumsfeld to Iraq last week to urge the nation's leaders to settle their differences and form a unity government.