The US Treasury sold $21 billion in 10-year bonds Wednesday that fetched a yield of 2.946 percent, up from 2.620 percent in the previous auction.
Investor demand jumped: The bid-to-cover ratio rose to 2.86, compared with 2.45 in the August 7 auction.
Direct bidders represented 29.59 percent of the sales at Wednesday's auction.
Indirect bidders, a group that includes foreign central banks bidding through the Federal Reserve, bought 36.60 percent of the bonds.
"As gauged by the strong demand from the investor base, it looks like people are coming out from the sell-off shadows, despite Fed uncertainty that lies ahead," Nomura analysts said in a research note.
"We believe this sort of demand is warranted given how much (US Treasuries) have cheapened and considering the fact that we think a lot of bad news has already been priced in."
Strong investor interest has the 10-year yield flirting with 3.0 percent as demand, measured by the bid-to-cover ratio, and direct bidding hit their highest levels since March, they noted.
Interest rates have climbed out of their low-level trend since the Federal Reserve signaled in May it could begin to reduce its massive monetary stimulus program this year if the economy continued to improve broadly.
Some economists expect the Fed to announce it will begin to taper its $85 billion a month bond-purchase program at next week's monetary policy meeting.