NEW YORK: US Treasury yields fell to six-week lows on Monday as investors piled into low-risk assets after China announced plans to impose additional tariffs on US-made goods in retaliation against a US increase in duties on Chinese imports on Friday.

China's finance ministry said earlier Monday it plans to set import tariffs ranging from 5% to 25% on 5,140 US products on a target list worth about $60 billion. It said the tariffs will take effect on June 1.

Beijing's response rattled already jittery investors who were caught off guard by last week's breakdown of efforts reach a trade deal between the world's biggest economic powers.

Investors and analysts are assessing the impact from this round of tariffs on global business activities.

"With rising protectionist measures, the damage to economic growth is increasing," said Stephen Gallagher, US chief economist at Societe Generale in New York.

Gallagher estimated the latest round of US and Chinese tariffs may reduce global economic growth by 0.15%.

At 10:05 a.m. (1405 GMT), the yield on the benchmark 10-year Treasury was 5.3 basis points lower at 2.4015% after touching 2.398%, the lowest since March 29.

Ten-year yields fell below those on three-month Treasury bills. A sustained inversion of this part of the yield curve has preceded every US recession in the past 50 years.

As investors shifted money into Treasuries, yen, gold and other safe-haven assets, they pulled money out of stocks and other risky investments. Wall Street's main indexes fell sharply in early trading with the S&P 500 losing 2.06%.