Britain cautioned Iran Monday that attempts to block the Strait of Hormuz or to strike at American military facilities in the Middle East could lead to escalation, even as Israel continued its strikes on Iran.

The war between Israel and Iran has raised concerns that Iran could try to close the Strait of Hormuz, the world’s most important oil chokepoint.

Naval forces in the Middle East warned that ships, especially U.S.-linked ones, could be at heightened risk after the U.S. strikes on Iran.