Oil and petrol prices have only risen modestly because of the crisis in the Gulf, but that could change.Read more
Business reporter, BBC News
Iran says it seized a "foreign tanker" and its 12 crew on Sunday for smuggling fuel in the Gulf.
State television quoted Iran's Revolutionary Guards as saying the ship had been smuggling one million litres (220,000 gallons) of fuel.
It is not yet confirmed if it is the UAE-based Riah tanker that stopped transmitting its position as it sailed through the Strait of Hormuz on Sunday.
That has forced up oil prices by about 1%.
Brent crude futures hit as high as $64.46 and West Texas Intermediate futures hit $57.32.
There's more detail on that story here.
Oil prices rose ahead of figures from the Energy Information Administration showing the level of crude inventories in the US.
Brent crude rose almost 1% to around $65 a barrel.
Abhishek Kumar, head of analytics at Interfax Energy, said: "Market participants are looking ahead to the weekly EIA oil inventory data for the US, which is expected to show yet another drawdown.
"Nevertheless, oil production in the Gulf of Mexico returning to normal following Hurricane Barry will limit price gains."
It might be Independence Day in the US, but not everyone is celebrating.
Oil prices fell around the world on Thursday, after latest data showed that US inventories fell less than expected, due to US refineries consuming less crude oil than the week before and processing 2% less oil than the same period in 2018.
Brent Crude Oil Futures fell 0.4% to $63.54 a barrel.
West Texas Intermediate meanwhile dropped 0.8% to $56.91 a barrel.