Dayton, D-Minn., said the office will be closed while Congress is in recess through Election Day, with his staff working out of his Minnesota office and in Senate space off Capitol Hill.
"I take this step out of extreme, but necessary, precaution to protect the lives and safety of my Senate staff and my Minnesota constituents, who might otherwise be visiting my Senate office in the next three weeks," he said on a call with reporters.
"I feel compelled to do so because I will not be here in Washington to share what I consider to be an unacceptably greater risk to their safety," he said.
CBS News Correspondent Bob Orr reports that federal officials said they knew of no new, specific intelligence information that would have prompted Dayton to close his office.
U.S. officials say they "know of no specific intelligence that al Qaeda is targeting Capitol Hill, Washington or any U.S. site, reports Orr. And there is no information that any attack is imminent.
Intelligence analysts from the Terror Threat Integration Center did brief members of Congress recently. But, officials say the information shared was "very general in nature -- along the same lines of the threat reporting we've been talking about all summer," reports Orr.
Brian Roehrkasse, a Homeland Security Department spokesman, said the department had no intelligence indicating al Qaeda intends to target any specific U.S. locations.
Added Capitol police spokesman Michael Lauer: "There's been no specific threats against the Capitol complex. We continue to be on guard now, all the way up to the election and all the way through the inauguration."
Dayton said he could not describe the contents of the top-secret intelligence report, which was presented to senators at a briefing two weeks ago.
"None of us can predict the future," he said. "I hope and pray that the precautions I've taken will prove unnecessary."
Asked what advice he would have for Minnesotans who want to travel to Washington over the next few weeks, Dayton said, "I wouldn't advise them to come to Capitol Hill. I would not bring my two sons to the capitol between now and the election."
Dayton issued a written statement that complained of inaction by Senate Majority Leader Bill Frist, R-Tenn.
"On three occasions, I have spoken personally with the Majority Leader and asked him to convene a meeting of all Senators to discuss this situation. I am dismayed, and perplexed, by his unwillingness to meet with us further about the information, which he initially brought to our attention. In the absence of that further discussion, I have made my own decision about my office, as is my responsibility," Dayton said.