Oil prices on Thursday hit fresh two-and-a-half year highs and were at levels last seen at the start of the commodity slump in 2014-15, with markets tightening amid tensions in Iran and due to ongoing Opec-led production cuts.
Prices were also buoyed by Asia's stock markets, which flirted with 10-year highs on Thursday amid strong data from leading economies including the US, Japan and Germany.
US West Texas Intermediate (WTI) crude futures were at US$62.10 a barrel at 0445 GMT, up 47 cents, or 0.8 per cent, from their last close. They hit $62.14 shortly before, the highest level since May 2015.
Brent crude futures - the international benchmark for oil prices - were at $68.13 a barrel, up 29 cents, or 0.4 per cent, after hitting a May-2015 high of $68.16 shortly before.
Beyond a brief intraday spike in May, 2015, these were the highest crude price levels since December, 2014, at the start of the oil price downturn.
Freezing weather in the US has also spurred short-term demand, especially for heating oil.
"The market is clearly getting more bullish on oil as inventory levels get closer to the five-year average. Geopolitical uncertainty in Iran, Opec's third-largest producer, is also helping to support the price as citizens are again protesting the government," said William O'Loughlin, investment analyst at Australia' Rivkin Securities.
Iran's elite Revolutionary Guards have deployed forces to three provinces to put down anti-government unrest that has been ongoing for a week, their commander said on Wednesday.
In the US, crude oil inventories fell by 5 million barrels in the week to December 29 to 427.8 million barrels, industry group the American Petroleum Institute said on Wednesday.
Potentially undermining the trend towards tighter market conditions is US oil production, which has risen by almost 16 per cent since mid-2016, hitting 9.75 million barrels per day (bpd) at the end of last year.
Official US Energy Information Administration (EIA) storage and production data is due on Thursday.