sentences:  However, oil prices rose early on June 5 because of concerns of disruptions caused by Gonu, as well as the threat of nationwide strikes in Nigeria, Africa's biggest oil producer.Crude oil for July delivery rose $1.13, or 1.7 percent, to $66.21 Monday on the New York Mercantile Exchange, the highest close in 15 days.Futures reached $66.48, the highest intraday price since April 30.