Oil prices on Friday headed for their lowest level since the middle of the coronavirus pandemic in 2021, affected by the blockade of new tariffs by US President Donald Trump and production increases announced by the OPEC+ producer group.

Brent futures fell by $2.29, or 3.3%, to $67.85 per barrel at 09:48 GMT. West Texas Intermediate U.S. crude futures fell $2.32, or 3.5%, to $64.63

The two benchmarks were on track for their biggest weekly percentage losses in six months.

The dollar index, which measures the value of the American currency against six other currencies, fell to 102.98, its lowest level since mid-October.

Between Trump's tariffs and increased OPEC+ production, “the oil complex could do little more than agree to the type of sales not seen since the collapse that occurred during the pandemic,” John Evans of oil broker PVM said in a note.

The fall in oil prices was fuelled by the decision of the Organization of Petroleum Exporting Countries and its allies, known collectively as OPEC+, to advance their plans to increase production.