A growing backlog of ships is piling up outside the Port of Rotterdam, as lashers continue their 48-hour strike over wage demands.

The Port of Rotterdam's lashers — who secure cargo to vessels — kicked off their strike on October 8, and plan to remain off duty until October 10, effectively halting all loading and unloading of vessels at Europe's busiest shipping hub. Reuters reports that as of October 9, the usual queue of six to seven ships at the port has doubled to 13 in the ensuing backlog. The union representing the port's lashers plans to meet with employers on October 10, but if a deal is not reached by then, the union has threatened to extend its strike through the weekend.

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Port officials have warned that disruptions could ripple across European supply chains if the stoppage persists. Delays have also been magnified by ongoing harbor pilot protests over federal pension reforms at Belgian ports in Antwerp, Zeebrugge and Ghent, where Rotterdam would typically look to reroute cargo in the event of a backlog. The Brussels Times reports that as of October 9, nearly 100 vessels were waiting to enter or leave ports in Antwerp, Zeebrugge and Ghent.