Oil prices were little changed in Asian trade on Monday with the market assessing news of the arrests of alleged militants plotting to bomb oil facilities in Saudi Arabia, dealers said.
They said the arrests sparked fresh concerns over possible terrorist disruption of supplies but for the moment, players were waiting cautiously for further developments.
At 9:40 am, New York's benchmark contract, light sweet crude for June delivery was four cents lower at USD 66.42 a barrel, down from USD 66.46 in late US trades on Friday.
Brent North Sea crude for June delivery was up one cent up at USD 68.42.
George Worthington, chief regional economist at Thomson IFR, said the arrest of 172 militants in oil kingpin Saudi Arabia "highlights the upside risk to oil prices."
Saudi Arabia, the world's biggest oil exporter, said on Friday it had seized arms and money, and rounded up 172 militants which it charged were plotting attacks.
"Some individuals were training to fly to carry out terrorist attacks ... Some of the cells arrested planned to target oil installations and refineries," interior ministry spokesman General Mansur al-Turki told.
Five of those detained were linked to a failed attempt to blow up an oil refinery, the world's largest, in Abqaiq in the oil-rich Eastern Province in February 2006, according to the ministry.