West Texas Intermediate futures for February delivery rose to $37.80 (+2.05%), while Brent crude advanced to $38.19 (+2.44%) after Saudi Arabia cut diplomatic relations with Iran in response to an attack of its embassy in Tehran. Recently Saudi Arabia executed Iranian citizens, who were accused of attacking public places in Saudi Arabia.

Both Saudi Arabia and Iran are major oil producers and these tensions raise concerns over stability of supplies, however the persistent global supply glut and recent weak economic data from China (world's second-biggest consumer of oil) limit bullish expectations.