U.S. oil futures settled with a loss on Friday, while Brent futures marked a high for the year and scored a gain for the week as strife in Yemen fed concerns over the potential for supply disruptions in the Middle East.

June crude settled at $57.15 a barrel, down 59 cents, or 1%, on the New York Mercantile Exchange. Compared with the end of last Friday’s session, prices were up about 2.5% from the settlement of the May contract, which was the front month at the time, but down 0.3% from the June contract’s close that day.

June Brent crude on London’s ICE Futures exchange rose 43 cents, or 0.7%, to $65.28 a barrel, trading at its highest levels since December. For the week, it saw a gain of roughly 2.9%. Both Brent and WTI crude futures settled Thursday at their highest levels since December, based on the front-month contracts.

“Hedge funds appear to be the primary force driving Brent futures to a year-to-date high, buying up a significantly higher-than-average volume of contracts on expectations that prices have hit their lows and will rally further from here,” said Katrina Lamb, head of investment strategy and research at MV Financial.

In Yemen, while reports emerged of fresh airstrikes on weapons depots and other military installations by Saudi Arabia on Thursday, an Iranian flotilla reportedly departed from the Gulf of Aden, which reduced the risk of a conflict at sea. “The Yemen situation triggered a J-shaped bounce—plummeting initially on reports that Saudi Arabia’s involvement in Yemen was waning before posting resurgent growth as reality dawned of continued heavy Saudi involvement,” said Matthew Parry, senior oil analyst at the International Energy Agency in Paris. The rest of the second quarter of this year should, however, “see precarious headwinds for price growth as overall market fundamentals point” toward a net second-quarter surplus, he said.

A continued fall in rig counts have fed expectations for a slowdown in U.S. output. Baker Hughes on Friday reported that the number of U.S. rigs actively drilling for oil fell 31 from last week to 703.

The recent rally in oil prices has prompted some banks and research houses to revise their price forecasts upward. Société Générale raised its Brent crude forecast for the full year by $4.33 to $59.54 a barrel. It also raised its Nymex crude forecast for the full year by $4.28 to $53.62 a barrel. However, it said oil prices in May and June will still be under pressure due to U.S. oil stockpiles rising by 1.9 million barrels a day in the second quarter.