Oil rose above the 70 usd mark this morning as further militant attacks in Nigeria and continued tight US gasoline supplies ahead of the peak summer driving season sparked a rally. Reports of an attack this morning by unidentified gunmen on France's Total oil facility in Nigeria, an OPEC member, added to instability. At 11.29 am London Brent crude for July delivery was up 65 cents at 70.07 usd per barrel, having hit an intra-day high of 70.29 usd. Meanwhile, New York crude for June delivery was up 36 cents at 65.30 usd a barrel. Nigerian production has been slashed by more than 25 pct as a result of militant attacks on oil fields. Violence has erupted further following last month's presidential elections. "We think there will be more and more of these attacks ahead of the handover to the new Nigerian government next week," said Michael Davies, an analyst with Sucden Research. On Sunday, Nigerian oil unions threatened to launch a strike beginning Thursday to protest the planned sale of two government-owned oil refineries in the city of Port Harcourt to private investors. Outgoing President Olusegun Obasanjo has authorised the sale to a newly formed company controlled by some of the ruling partys largest campaign donors. In the US, concerns remain whether refineries can meet stronger gasoline demand which will peak during the summer when Americans take to the highways during the holiday driving season. The season begins on the May 26-28 weekend. US government data, released last week, showed gasoline inventories are more than 7 pct below their five-year average for mid-May. Analysts said US refineries are running seven weeks behind normal schedule this turnaround season, after taking an extra seven or eight weeks in the fall to maintain refineries. Continued production outages and unscheduled maintenance throughout refineries in US means that a solid 15 weeks of higher utilisation has been lost since September.