Devastating floods across central China temporarily affected the power supply to the world’s biggest iPhone manufacturing plant in Henan province.

The plant in Zenghzhou Technology Park is operated by Foxconn of Taiwan and employs up to 120,000 people.

It is the single biggest single manufacturer of devices for Apple globally and, together with two other campuses in the same city, produces over half of the world’s iPhones.

Foxconn said it had been forced to implement an emergency response plan in the city of over 10 million people where at least 25 people have died, although it said iPhone manufacturing activities have not been affected.

The floods have come at a critical time for Apple’s global iPhone supply chain, which is gearing up for the launch of new models in September.

Manufacturing of the new models usually starts in July and ramps up in August to prepare for a surge of demand in the final four months of the year.

“Our thoughts are with everyone affected by the flooding across Henan province, and the first responders helping people to safety,” chief executive Tim Cook said on his Weibo account, a Chinese social media platform.