Oil jumped about 5 percent on Thursday, the biggest daily gain in a month, as airstrikes in Yemen by Saudi Arabia and its Gulf Arab allies sparked fears that escalation of the Middle East battle could disrupt world crude supplies.

The Saudi military operation against the Iran-backed Houthi rebels, who have driven Yemen's president from the capital Sanaa, has not affected oil facilities of major Gulf producers.

But fears the conflict could spread and disrupt Middle East shipments powered benchmark Brent oil to near $60 a barrel, in its biggest daily gain since Feb. 25.