Orlando gunman left chilling Facebook posts, U.S. Senate committee says

Orlando gunman Omar Mateen apparently made a series of Facebook posts and searches, raging against the "filthy ways of the west" and blaming the U.S. for the deaths of "innocent women and children," according to a U.S. Senate committee letter released Wednesday.

The killer whose rampage left 49 people dead also searched for "Pulse Orlando" and "shooting" online on the morning of the carnage Sunday and said on Facebook: "America and Russia stop bombing the Islamic state," according to the letter.

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The Senate Homeland Security and Governmental Affairs Committee sent the letter to Facebook CEO Mark Zuckerberg, asking the company to produce information on Mateen's online activity and to provide a briefing to the panel.

The letter illuminating Mateen's state of mind in the final hours of his life was released as the long, sad procession of memorials and funerals for the victims began in Orlando and as the FBI appealed for the public's help in reconstructing the killer's movements.

The FBI is also trying to establish how much Mateen's wife may have known about the attack at Pulse dance club.

"We need your help in developing the most complete picture of what he did and why he did it," FBI agent Ron Hopper said at a news conference.

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In its letter, the committee said staffers have learned that five Facebook accounts were associated with the 29-year-old American-born Muslim.

"The real Muslims will never accept the filthy ways of the west," Mateen wrote, according to the letter from committee chairman Sen. Ron Johnson, a Wisconsin Republican. Johnson did not say how he learned of the posts other than to cite "information obtained by my staff."

As he did in his call to a 911 operator during the massacre, Mateen pledged his allegiance on Facebook to the leader of ISIS, and in his final post warned: "In the next few days you will see attacks from the Islamic state in the USA."

Despite his professed loyalty to the extremist group, the Obama administration has said it has seen no evidence that the shooting rampage was directed by ISIS.

A spokesman for the FBI did not immediately return a call for comment Wednesday evening, and Facebook had no immediate comment.