The price jumps erased much of Wednesday's declines on the hopes of an imminent deal to end the conflict that has all but halted shipping through the crucial Strait of Hormuz for months.
An American official said the military had shot down four Iranian drones and struck a control centre in the southern city of Bandar Abbas.
The official, speaking to AFP on condition of anonymity, described the latest actions as "measured, purely defensive, and intended to maintain the ceasefire".
Tehran's state media said Iranian forces had fired at four ships in the strait, while Kuwait said its air defences were responding to missile and drone attacks.
The developments came despite an Iranian official saying renewed hostilities with the United States were unlikely, and a threat from US President Donald Trump to "finish the job" if a peace deal was not reached.
The mixed signals underscored the fragile state of talks aimed at ending the Middle East war, which has profoundly shaken global energy markets.
Brent North Sea crude, the main international benchmark, rose more than two per cent during Thursday trade to nearly $97 a barrel, while the main US contract, WTI, increased at a similar pace to around $91 a barrel.
Stock markets across Asia saw losses on Thursday, with main benchmarks in Hong Kong, Taipei and Sydney closing more than one per cent lower.
Tokyo and Seoul saw more moderate declines, while Shanghai was the sole major exchange to buck the trend, finishing the day up 0.1 per cent.
During morning trading in Europe, London fell nearly one per cent while Paris was down 0.4 per cent. Frankfurt was flat.
The drops came after a strong day for global stocks on Wednesday, as investors, bullish on artificial intelligence, looked past the conflicting headlines on Iran.
In Asia, South Korean chipmaker SK hynix hit a $1 trillion market capitalisation, placing it alongside regional tech heavyweights Samsung Electronics and TSMC, as well as US chipmaker Micron.
The tech surge has coincided with a persistent spike in energy prices, threatening several major Asian economies that rely on oil shipments from the Middle East.
Economists warn that central banks may have to raise interest rates if inflation worsens due to the war, thereby increasing borrowing costs and potentially weighing on economic growth.
On Wednesday, "every headline pulled the market in a different direction, leaving traders with the same conclusion they have been wrestling with for weeks", said Stephen Innes at SPI Asset Management.
"The Strait may eventually reopen fully, but until there is something more concrete than draft frameworks and political theatre, every barrel remains hostage to headline volatility, even if sub-$100," he said.
Key figures at around 0830 GMT
Brent North Sea Crude: UP 2.5 per cent at $96.65 a barrel
West Texas Intermediate: UP 2.4 per cent at $90.84 a barrel
Hong Kong - Hang Seng Index: DOWN 1.3 per cent at 25,006.16 points (close)
Tokyo - Nikkei 225: DOWN 0.5 per cent at 64,693.12 (close)
Shanghai - Composite: UP 0.1 per cent at 4,098.64 (close)
London - FTSE 100: DOWN 0.9 per cent at 10,412.29
Euro/dollar: DOWN at $1.1608 from $1.1629 on Wednesday
Pound/dollar: DOWN at $1.3397 from $1.3434
Dollar/yen: DOWN at 159.52 from 159.53 yen
Euro/pound: UP at 86.65 from 86.59 pence
New York - DOW: UP 0.4 per cent at 50,644.28 (close)
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