A two-year-old boy is missing at the site of a fire that destroyed a barn in Woolwich township.

The Wolwich fire department says crews were called to a dairy farm on Lobsinger Line just after seven o'clock on Friday.

When they arrived, the barn was engulfed and the child, who lives on the property, was nowhere to be found.

Deputy Fire Chief Dale Martin of Wolwich township fire says that Waterloo Regional Police helped set up a search. "We set up the whole property with police and neighbours," Martin says. "We're unable to locate the child."

The boy was believed to be with a dog when he was last seen on the farm. The dog is also missing.

Some cattle were in the barn. It's not known how many escaped, but a neighbour opened a door to let some out.

As many as 35 firefighters from four stations were on the scene at one point.

It's not yet known what caused the fire. The Ontario Fire Marshal's office is being called in to investigate.

Fire crews are expected to stay on scene until they find the child.