On the evening of April 18, the Iranian Islamic Revolutionary Guard Navy announced that the Strait of Hormuz would be closed until the US lifted the blockade, and warned "no ships are allowed to leave their anchorage in the Persian Gulf and the Oman Sea; any approach to the Strait of Hormuz will be considered cooperation with the enemy" and will be attacked.
The new attacks on this maritime route threaten to exacerbate the world energy crisis and push the parties back to fighting as the conflict enters its 8th week.
A fragile ceasefire agreement is expected to expire on April 22. Iran said it has received new proposals from the US, while the intermediary Pakistan is trying to arrange a new round of direct negotiations.
Previously, the Iranian joint military command announced that "control of the Strait of Hormuz has returned to its former state... under the strict management and control of the armed forces".
According to the UK Maritime Trade Coordination Center (UKMTO), Revolutionary Guard's high-speed trains fired at a tanker, and an unidentified object hit a container ship, damaging several containers.

The Indian Ministry of Foreign Affairs said it summoned the Iranian ambassador after the "serious incident" when 2 Indian-flagged commercial ships were shot, especially in the context that Iran had previously allowed some ships heading towards India to pass through.
For Iran, closing the strait is considered the strongest "weapon", which can put great pressure on the global economy and create political pressure on President Donald Trump.
On the US side, the blockade continues to maintain pressure and could stifle Iran's already weakened economy.
On April 18, Iran's Supreme Leader Ayatollah Mojtaba Khamenei issued a tough statement, affirming that the country's navy is "ready to infringe bitter defeats on the enemy".
A day earlier, on April 17, Iran announced the reopening of the strait for commercial ships after reaching a 10-day ceasefire between Israel and Hezbollah forces in Lebanon.
However, President Donald Trump affirmed that the blockade of Iranian ports "will still be fully maintained" until Tehran reaches an agreement with the US.
The US Central Command (CENTCOM) said US forces have forced 23 ships to return to Iran since the blockade took effect earlier this week.