On the London market, a barrel was trading at a price of $1.31 lower than at the close of trading at the end of last week, at $101.83. On the US market, it was $3.46 cheaper and cost $95.25, Hrportfolio reports.
Market sentiment was marked at the beginning of the week by estimates that oil from the Middle East was still reaching buyers in Asia.
Iran took control of the Strait of Hormuz after the US-Israeli attack, banning transit for ships affiliated with the US, Israel, European countries and their allies.
The strait is not blocked, Iranian Foreign Ministry spokesman Esmaeil Baghaei said on Thursday, adding, according to a report by Iran's Mehr news agency, that ships transiting must coordinate with the Iranian navy to maintain navigation safety.
Iranian Foreign Minister Abbas Araqchi stressed on Monday that the strait is "closed only to enemies who cowardly attack Iran."
Analysts concluded at the beginning of the week that Iran was not in the interest of a severe price shock in oil markets.
With the porous Hormuz, Tehran is signaling determination and simultaneously "adjusting" the level of disruption so as not to turn away partners, believes Vezina-Poirer of BCA Research. The market is noticing that oil from the region is still reaching buyers in Pakistan, India and China.
A complete closure of the strait could be a trigger for a multinational operation to open it by military force, notes a BCA Research analyst.
US President Donald Trump, meanwhile, called on allies to support the transit operation, but the response was largely negative.
Over the weekend, the US attacked the Iranian island of Kharg in the northern Persian Gulf, Iran's main port terminal for oil exports, bypassing oil infrastructure.
Japan, meanwhile, announced that it would release 80 million barrels from reserves to the market as early as Monday, which should cover consumption for approximately 45 days.
Members of the International Energy Agency (IEA) unanimously supported a proposal to release 400 million barrels from reserves to the market to secure supply and mitigate sudden price fluctuations.
The Asia-Oceania region should immediately put almost 109 million barrels of oil and petroleum products on the market, IEA data released on Sunday showed.
The release of barrels from reserves brings "a significant and welcome respite," the agency said, but regular transit through the Strait of Hormuz will play the most important role in normalizing supply, the IEA stressed.
Separate OPEC calculations show that a barrel of its members' basket of oil was up $6.04 on Friday, costing $126.9.
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