The number of Americans filing for unemployment benefits fell last week, a sign the labor market was holding firm despite tensions between the United States and its trading partners that have spawned restrictions on global commerce.

Initial claims for state unemployment benefits slipped 2,000 to a seasonally adjusted 210,000 for the week ended Aug. 18, the Labor Department said on Thursday.

It was the third straight week of declines for claims, which have dropped so low that economists have scrambled for explanations. In July, claims fell to their lowest level since 1969 even though the workforce is much larger than in prior decades.

Economists polled by Reuters ahead of Thursday's report had forecast claims rising to 215,000 in the latest week.

The signs of strength in the U.S. labor market have been a key reason behind the Federal Reserve's ongoing campaign to raise interest rates.

Minutes of the U.S. central bank's last policy meeting, published on Wednesday, showed officials discussed raising rates soon to counter excessive economic strength, although policymakers also examined how global trade disputes could batter businesses and households.