Oil prices steadied 1% higher on Wednesday, well below peaks hit in frenzied trading earlier in the day after a rocket attack by Iran on US forces in Iraq.
Prices spiked at morning, rising over 4.5 percent at one point, after Tehran fired a barrage of ballistic missiles against two airbases used by US and coalition forces.
This marked Iran's first response to the US killing of top Iranian commander Qasem Soleimani in an airstrike in Baghdad on Friday.
The retaliation shook global financial markets, with S&P futures tumbling as much as 1.7% and the benchmark US 10-year Treasury yield falling to a one-month low, Reuters reported.
Stock markets in Europe were also indicated lower.
The benchmark West Texas intermediate (WTI) jumped as much as 4.53 percent to $65.54 a barrel before settling down slightly.
Meanwhile, gold prices surged more than 2% on Wednesday, crossing the key $1,600 mark, while silver jumped 1.2% to $18.60 per ounce, after hitting its highest since late September at $18.71.
Tokyo's benchmark Nikkei index also plunged nearly 2% Wednesday morning.
According to Reuters, some analysts said the attacks could provide investors an excuse to pull back from equities after improving global sentiment and an imminent US-China trade truce recently propelled the benchmark S&P 500 to record highs.
"We've had three months of asymmetric upward moves in the equity markets," said Christopher Stanton, chief investment officer at San Diego-based Sunrise Capital LLC.
"Things have become increasingly overbought. If you're an investor, don't you want to take it easy here and back off a bit?," he added.