Stocks fell on Monday after the U.S. and Iran traded fire for the first time in a month.

Dow Jones Industrial Average traded 208 points, or 0.39%, lower. S&P 500 futures slipped 0.24%, as did Nasdaq.

On Sunday, U.S. Central Command confirmed to MS NOW that the U.S. struck two rocket launchers on Iran’s Larak Island.

Sunday’s attack was the first publicly acknowledged U.S. strike on Iranian positions since late July, with Iranian state media reporting that Tehran had attacked U.S. bases in Jordan in retaliation.

Oil prices jumped after the hostilities resumed. U.S. West Texas Intermediate oil traded more than 3% higher at above $86 per barrel, while global benchmark Brent crude oil futures were up more than 3% at above $91 a barrel.

Heightened tensions in the Middle East have contributed to choppy trading in August, but Wall Street is currently on track for a month of broad gains, led by the tech sector.

The Dow is up 2.1% month-to-date, putting the index on track for its fifth consecutive monthly advance. The S&P 500 and Nasdaq Composite were headed for their first one-month increases since May, up about 3% and 4%, respectively. Both the S&P 500 and Dow also reached all-time highs earlier in August.