Oil prices advanced during the opening session on Monday on positive news of the vaccine rollout in the US and UK and an attack on a tanker off the coast of Saudi Arabia.
Brent, the international benchmark, was up 1.08 per cent trading at $50.51 per barrel at 1.11pm UAE time, while West Texas Intermediate, the key gauge for US oil, was up 1.07 per cent at $47.07 per barrel.
The benchmarks moved higher following an attack on BW Rhine, a Singapore-flagged vessel discharging refined products off the western coast of Saudi Arabia.
Hafnia, which owns the vessel, confirmed in a statement on Monday that the carrier had come under attack just after midnight local time from an "external source".
The vessel halted discharge operations and switched to emergency procedures onboard. All 22 crew onboard escaped with no injuries, while the fire onboard the ship was brought under control.
The latest incident comes weeks after Greek vessel Agrari was damaged in an attack attributed to the Houthis, while it was offloading oil at the Red Sea Shuqaiq port.
Earlier, a missile fired by the rebels struck a Saudi Aramco oil depot in Jeddah.
The latest incident echoes a spate of attacks on tankers transiting the Strait of Hormuz, to the east of the Arabian Peninsula last year.
In May 2019, four tankers off the coast of Fujairah were attacked in what authorities said appeared to be sabotage.
A couple of months later, Iran's Islamic Revolutionary Guard Corps captured the British-flagged Stena Impero as it was en route to the port city of Jubail in Saudi Arabia.
Brent surged above $50 per barrel for the first time since March as optimism rose over the containment of the pandemic as developed nations including the UK and the US rolled out an inoculation programme.
The UK has begun administering doses to elderly at-risk populations, while the US, which is nearing 300,000 deaths from Covid-19 will begin distributing vaccines across all 50 states this week.