Concerns over fuel supplies are growing as hopes for an extension of the Iran-US ceasefire fade. 

Brent crude rose 27 cents to 91 dollars and 14 cents a barrel in late Monday trading. It had already reached its highest level since late July in the previous session.

Meanwhile, US West Texas Intermediate, or WTI, rose 42 cents to 85 dollars and 4 cents a barrel. 

Market experts fear prices could rise further if oil supplies from the Middle East are disrupted.