WINTHROP, Iowa -- Around 4,800 pigs have been killed in a fire at a confinement facility in northeast Iowa.

Buchanan County firefighters were dispatched around 8:30 p.m. Wednesday. The fire started in one confinement building and spread to another.

No injuries to workers or firefighters were reported. An official says 3,000 piglets and 1,800 sows were killed.

The cause of the fire is under investigation.