London-traded Brent crude rallied 3% to $113 today as the security situation in Iraq continued to deteriorate.
The Wall Street Journal reported Iran had deployed Revolutionary Guard units to Iraq to defend against a violent Sunni insurgent group that has already seized Iraq's second-largest city. Iraq's leadership is largely Shia, which is also the majority religion in Iran.
President Obama said his administration had "not ruled anything out" to defend Iraq's elected leaders.
NYMEX-traded crude climbed more than 2% to $106.