Shanghai is facing new anti-Covid measures as the city faces its biggest outbreak since the pandemic began.
Localised lockdowns and stricter testing of workers could disrupt operations at the world's biggest port, the port of Shanghai.
The port has already been becoming congested as a result of carriers redirecting ships from Ningbo, ironically because of another outbreak there. Schedules for container ships are now running a week behind schedule at Shanghai.
If a major outbreak at the port occurs it could have a disastrous effect on shipping out of China, and therefore a knock-on effect on supply chains in the US and Europe.
Hopefully the port itself will remain open, but even if it does large numbers of workers are likely to to either be infected themselves or forced to quarantine. This will decrease efficiency and slow the flow of cargo through the port, creating further delays.