Warning sirens sounded throughout the northern province of Friesland on Friday morning following a nitric acid leak at a dairy factory in the village of Dronrijp.

But the alarm was only meant for people living in the village itself, to tell them to keep their doors and windows shut until given the all-clear, local paper Leeuwarder Courant said.
Roads were also closed for a time, the paper said.
Several people were taken to hospital with breathing problems and others complained of eye irritations as the acid cloud moved over the village. It then drifted northwards and broke up, the paper said.
The Leeuwarder Courant says a hose snapped when a lorry was delivering its load of nitric acid to the Friesland Campina factory in the village. Nitric acid is used as a cleaning product in the dairy industry.
It is not clear from the media coverage so far if the sirens sparked panic outside the affected region. But some locals have accused the authorities of over-reacting by declaring the leak an official disaster.