WASHINGTON - President Obama succumbed to days of withering criticism Wednesday, releasing dozens of emails in an effort to demonstrate that the White House did not try to cover up information about the September 2012 attacks on diplomatic facilities in Libya that killed four Americans.

The documents show that substantive changes to a set of talking points intended for use by Congress about the attacks were made by the CIA.

References to al-Qaida, an al-Qaida-linked terrorist group operating in eastern Libya and prior terrorist attacks in the region were removed from the talking points by Michael J. Morell, the deputy director of the CIA, who in a single editing effort shrank the list of bullet items in the document from five to three, according to the White House-released documents.

The documents do not provide a complete record of how the talking points were drafted, and at least one of them contradicts the version of events that administration officials gave reporters Wednesday. That email suggested that Jake Sullivan, a State Department official who is now Vice President Joe Biden's national security adviser, and Ben Rhodes, Obama's deputy national security adviser, were involved in the final version of the points, but the administration officials said that was untrue.

The release of the emails came late Wednesday as Republicans on Capitol Hill continued to hammer Obama over whether his administration could have prevented the attack that killed a U.S. ambassador and whether his aides spent months hiding information to protect Obama's re-election chances. The emails make no mention of presidential politics, however.

The White House has struggled with its response, accusing Republicans of leaking parts of the emails to "politicize" the issue. Spokesman Jay Carney repeatedly refused requests to release the emails, saying lawmakers had already seen them. Aides finally released the documents at a briefing with a select group of reporters.

The White House distributed a binder of 100 emails that the administration sent to Congress in February and March but never released to the public. Many names and email addresses were redacted.

The emails, stretching for 30 hours between Sept. 14 and Sept. 15, show that the original talking points originated in the CIA's Office of Terrorism Assessment and were revised a total of five times, generally in minor ways, until Morell made his sweeping edits. The White House made only one small word change after Morell's revision.

The emails show that State Department spokeswoman Victoria Nuland became involved in the drafting process after the fourth version. In her first comments, she noted that the talking points went beyond what she had been telling reporters, and that if the talking points said extremists were involved in the attacks, "I'll need answers" to questions she anticipated reporters would ask "if we deploy that line."

Later, she expressed "serious concerns" about "fingering" a local extremist group, Ansar al Shariah, "when we aren't doing that ourselves until we have investigation results."

She also objected to a talking point that said the CIA had issued several warnings about extremist activities in Benghazi and eastern Libya. "That point," she said, "could be abused by members (of Congress) to beat the State Department for not paying attention to agency warnings. So why do we want to feed that either?"

Nearly two hours later, Nuland sent a third email, saying "my building leadership" was unhappy with the points and was consulting with "NSS," a reference to the staff of the National Security Council.

It was after that email that Morell made his major edits, which eliminated the same sections Nuland had objected to and others. But the document is handwritten and does not contain a time stamp. The senior intelligence official said Morell made his revisions the night of Sept. 14 and had not seen Nuland's emails before doing so.

His version was circulated to other senior intelligence community officials by email at 9:46 a.m. on Sept. 15.

The final version was also shared with CIA Director David Petraeus at 12:51 p.m. in an email from the CIA's Office of Congressional Affairs. Petraeus raised questions but said the decision was up to the National Security Council.