Treasury bonds strengthened Monday as political disturbance in Hong Kong added to concerns over the global economic outlook and boosted demand for haven assets. In recent trading, the benchmark 10-year note was 13/32 higher, yielding 2.486%, according to Tradeweb.

The yield traded at the lowest level in more than two weeks. Yields fall as prices rise.

Investors are concerned that the city’s crackdown on pro-democracy protests threatened to disrupt businesses and weigh on retail sales ahead of China’s National Day holiday on Wednesday. The protests are centered on Beijing’s decision to impose limits on how Hong Kong elects its leader.

The clashes come at a time when investors are grappling with an uneven pace of the global economic growth and ongoing geopolitical risks in Ukraine and the Middle East.

“Treasury bonds are benefiting from the risk off move,” said Larry Milstein, head of government and agency trading at R.W. Pressprich & Co. in New York.

Stocks in Hong Kong sank by nearly 2% Monday and the selling spread to equity markets in Europe and the U.S.

“At this point the heightened tensions is providing just the latest distraction for the market that has been on edge due to concerns of other geopolitical concerns,” said Adrian Miller, director of fixed income strategy at GMP Securities. “Depending on how the protests advance, the situation in Hong Kong could increasingly become problematic for mainland China and the governments ability to institute reforms while also boosting growth.”

The haven demand for now offset the selling pressure on Friday partly driven by Bill Gross’s abrupt departure from Pacific Investment Management Co.

Mr. Gross is one of the biggest names in fixed income investing and the $222 billion Pimco Total Return Fund he managed is the world’s largest bond fund by assets. The fund held 41% of its investments in U.S. government-related holdings as of the end of August, a proxy for Treasury bonds.

On Friday, bond prices pulled back over concerns that Mr. Gross’s departure could lead to large client redemption from the fund and force the fund to sell its bond holdings to meet the outflows.

Some strategists said it was just a knee-jerk reaction to the news and that the Treasury bond market, at $12 trillion in size, will be moved by fundamental factors such as the economic outlook and the path of the Federal Reserve’s interest rate policy.

A report Friday showed the U.S. economy grew at a rate of 4.6% in the second quarter, up from a previous estimate of 4.2%. The result, in line with expectations, indicated the U.S. economy has gained traction after the winter doldrums.

Bond investors are keeping a close eye on the health of the U.S. economy as the Fed is widely expected to start raising its short-term interest rates sometime next year. Higher interest rates make newly-minted bonds more attractive to buy, diluting the value of existing bonds.

Fed policymakers have showed patience in moving into higher interest rates, partly because inflation, especially wage growth, has remained contained.

Concerns about the Fed’s interest rate outlook pushed the 10-year Treasury yield above 2.65% earlier this month to a two-month high.