Oil prices rose again on Monday, extending multi-week gains as the energy crisis gripping major economies shows no sign of easing. Amid a pick up in economic activity and restrained supplies from major producers, US oil rose $1.95, or 2.5 percent, at $81.30 a barrel, the highest since late 2014. Brent crude was up $1.62 cents, or 2 percent, at $84.01 a barrel, the highest level since October 2018. Prices have risen as the removal of coronavirus restrictions globally and high vaccination rates in many countries has led to a revival in economic activity, with Brent crude advancing for five weeks and US crude for seven. In addition, The Organization of the Petroleum Exporting Countries (OPEC) and allies, together called OPEC+, last week decided to maintain a steady and gradual increase in production.