US starts naval blockade of Iranian ports after deadline passes

Cargo ships in the Gulf, near the strait of Hormuz. The US has said the blockade applies to ships entering or leaving Iranian ports or coastal areas. Photograph: Reuters

The US blockade of ships using Iranian ports in the Gulf has come into effect, turning the six-week-old conflict between the US-Israeli coalition and Iran into a test of economic endurance.

US Central Command (Centcom) made no formal announcement of the start of the blockade but had said it begin on Monday at 5.30pm Iranian time and would apply to any ships entering or departing Iranian ports or coastal areas, while ships using non-Iranian ports would not be impeded.