The vital Strait of Hormuz will now be “closed to all vessels” Iran’s Islamic Revolutionary Guard Corps (IRGC) said after the US launched new strikes on Iran.

“Effective immediately, due to insecurity in the region, the Strait of Hormuz is declared closed to all vessels, including oil tankers and commercial ships,” the IRGC said in a post on its official Telegram. “Any vessel attempting to transit the strait will be targeted.”

US Central Command (CENTCOM) pushed back on the Iranian claim, saying that commercial ships continue to transit in and out of the strait – which the IRGC denied. Earlier, Iran’s semi-official Fars News Agency said two ships attempting to “transit the Strait of Hormuz illegally” had been struck.

Meanwhile, Iranian state news agency IRNA claimed there had a “confrontation” between IRGC navy units and US forces in the strait and that the IRGC’s “resistance and heavy fire” had left US forces “shocked.” CENTCOM, however, said no US warships were hit.

The critical waterway has been choked off for months because of the war, with visible traffic through the strait estimated to be just 15% of pre-war levels, according to JPMorgan.

Since the conflict began, Iran has threatened to strike any vessel passing through without permission from the IRGC. Last month, it laid out new rules for ships seeking to pass through.

-CNN