Sen. Hillary Rodham Clinton acknowledged today that she had erred when she claimed that she had arrived under sniper fire in Bosnia, but insisted the mistake did not reflect poorly on her ability to serve as commander-in-chief.

Speaking at a wide-ranging televised news conference from Pennsylvania where she was campaigning for the Democratic presidential primary on April 22, Clinton said her comments about the sniper fire were an error.

"So I made a mistake, that happens," she said when the question was raised again. "It proves I'm human -- which for some people is a revelation."

In campaign appearances, Clinton has cited her experience as first lady as one of her qualifications to be president and as one of the areas that distinguishes her from Sen. Barack Obama. She has cited her efforts to help in a variety of global hot spots including Ireland and Bosnia, which she visited in March 1996.

"I remember landing under sniper fire," Clinton recalled during a speech last week in Washington, reading from prepared remarks. "There was supposed to be some kind of a greeting ceremony at the airport, but instead we just ran with our heads down to get into the vehicles to get to our base."

Her recollection has come under verbal fire with newspapers publishing pictures of her peacefully greeting schoolchildren. The cable television networks have repeatedly run video of her calmly walking from helicopter, accompanied by soldiers and her daughter, Chelsea, to greet the children.

"You know, I made a mistake in describing it," said Clinton, adding that the Secret Service and the military had warned her to take precautions.

"I did make a mistake in talking about it the last time and recently," she said. "But this is really about what policy experience we have and who is ready to be commander-in-chief and I am happy to put my experience up against Sen. Obama's any day."

The Obama campaign has claimed Clinton's misstatement is part of a pattern by the New York senator to inflate her credentials. But Clinton insisted there was no such pattern.

"I just disagree with that. I made a mistake and I had a different memory," she insisted.

Obama has no public schedule today, but his campaign posted his tax returns on its website, a move designed to pressure Clinton to release her financial information.

The campaigns have sparred over tax and financial information before. For the Obama campaign, the issue is part of its effort to portray the New York senator as hiding key information or in some case exaggerating it.

Obama's tax returns from 2000 to 2006 were posted this morning, the campaign announced. Much of the information had been previously released to news organizations.

For the tax years of 2005 and 2006, Obama and his wife Michelle jointly reported about $2.6 million in total income, according to the returns. Most of the income came from Barack Obama's success as an author.

Politicians often celebrate the April 15 tax deadline by releasing their returns, a move praised by good government groups. Those who don't release their taxes often find themselves attacked by their opponents.

"Releasing tax returns is a matter of routine and we believe the Clinton campaign should meet that routine standard and meet that routine standard now," according to Robert Gibbs, Obama's communications director.

Clinton has said she will release her post-White House tax documents in mid-April.

The Clinton campaign this morning attacked Obama for not making his tax returns public, but the statement came at almost the same moment as the Obama campaign's actions.

"In the public record there are 20 years of Hillary's tax returns, hundreds of thousands of pages of records from her time in White House and countless other documents detailing her time in public life. Sen. Obama's record is far more opaque. Sen. Obama has not released his tax returns, except for 2006," Clinton spokesman Phil Singer said in a statement sent to reporters.

The tax issue came up in Clinton's 2000 Senate campaign, but in a different way. Republican candidate Rick Lazio was followed by a protester who called himself Tax Man, demanding that Lazio makes his documents public.

The Clinton campaign used the issue to embarrass Lazio.

Clinton was campaigning in Pennsylvania today while Obama had no public schedule.

Arizona Sen. John McCain, the presumptive GOP presidential nominee, is likely to release his tax returns the week of April 15, according to his campaign.

michael.muskal@latimes.com

Times staff writer Maeve Reston, with the McCain campaign in Santa Ana, contributed to this story.