Container ship congestion in Singapore, one of Asia’s busiest ports, is spreading to neighboring Malaysia, snarling supply chains and causing delays in the movement of consumer goods. 

Around 20 container vessels are anchored in a cluster off Port Klang, on the western coast of Malaysia near Kuala Lumpur. Both Klang and Singapore sit on the Straits of Malacca, a vital waterway that links Europe and the Middle East to East Asia. 

The maritime logjam is being caused by ships avoiding the Suez Canal and Red Sea due to attacks by Houthi rebels, who support Hamas in the war with Israel. Many vessels heading toward Asia are opting to travel around the southern tip of Africa, meaning they’re not able to refuel or unload cargo in the Middle East.

Port Klang is an important terminal, given its proximity to Kuala Lumpur, but a queue of this magnitude is rare, with ship-tracking images showing many vessels unloading at its berths. Slots at Singapore and Tanjong Pelepas, a Malaysian port just across the border from the city-state, also appear to be full, but there are fewer ships waiting off those terminals. 

Congestion at the shipping terminals could last through August, analysts have said. Container vessel rates have surged as a result of the delays and rerouting.