A 46-year-old farmer was shot through his bedroom window while sleeping on his farm near Potchefstroom, says the North West police.

The man was shot around midnight on Saturday on the farm Rietfontein in the Buffelshoek district, between Potchefstroom and Parys, spokeswoman Inspector Wilmarie van der Merwe said.

A shotgun was used in the attack.

"They (the attackers) did not break into the house and nothing was stolen."

Police did not know the motive of the shooting, nor how many attackers there were.

The man's father, who lives with him on the farm, was also in the house at the time of the shooting, but was not injured.

ER24 spokeswoman Vanessa Jackson said the man was taken to Potchefstroom Provincial Hospital.

"He had multiple wounds on the right-hand side of his back. His wounds are deemed to be critical."

A case of attempted murder was opened.