By Andy Sullivan

WASHINGTON, March 19 (Reuters) - Thirty-two people were arrested on Wednesday when they tried to block entrances to the Internal Revenue Service in protests marking the fifth anniversary of the U.S. invasion of Iraq, police said.

Protesters had planned to shut down the building that houses the U.S. tax-collection agency, one of several antiwar events planned across Washington as the Iraq war enters its sixth year.

Ernestine Fubbs, a spokeswoman for Immigration and Customs Enforcement, the police agency that oversaw the protest, said 32 people were arrested at IRS when they crossed barriers set up by police in front of the building's entrances. Other police officials said the event was nonviolent.

One hour after the standoff started, several dozen protesters waved signs that said "Stop Paying to Kill" and "How Much Longer?" as a ragtag brass band played. IRS employees were easily able to enter the building.

"We wanted to put our bodies between the money and what that money goes to fund -- the war, the occupation, the bombs," said Frida Berrigan, an organizer with the War Resisters League.

"It would have been nice to shut down the building for the whole day but I think this was a good symbolic action," she said.

In a separate event on the National Mall, about 100 protesters with the antiwar group Veterans for Peace carried signs that read "the endlessness justifies the meaninglessness" and waved upside-down U.S. flags, a traditional sign of distress.

"Bush and Cheney belong in jail," they chanted, referring to U.S. President George W. Bush and Vice President Dick Cheney.

Later, scores of noisy protesters blocked a busy intersection in the city's business district.

Berrigan said she was disappointed that antiwar protests have shrunk in size over the past five years, in contrast to the massive protests of the Vietnam War era.

"The war is an abstraction to a majority of Americans," she said. (Additional reporting by Lisa Lambert; editing by Mohammad Zargham)

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