An explosion has ripped through a machine room at the giant power station on the Norman coast at Flamanville this morning, injuring five workers but not resulting in any leakage of radioactivity, French authorities reassured.
The blast occurred at 10am French time in a machine room and sent smoke into the air above one of the reactors at the site causing concern to local residents.
There are reports of an explosion at the Flamanville nuclear power station in France.
ITV Channel TV understands the blast was not in a radioactive part of the plant and there is no nuclear risk, although it is not yet known whether there have been any casualties.
There are also reports of fire on site.
The power station can be seen from both Jersey and Guernsey on a clear day.
Jersey Met issued the notice, after one of its seismometers picked up an earthquake in the English Channel, of 2.6 magnitude.
The fire at the Flamanville plant was "immediately" brought under control and there was no radiation leak or injuries, operator EDF said.
The blast occurred at 10am French time in a machine room and sent smoke into the air above one of the reactors at the site.