ABUJA -- At least two people were killed and 18 others were rescued after a wooden boat capsized in Nigeria's northern state of Jigawa late Sunday, police said on Monday.

The boat, carrying a group of some 20 local traders, was en route to the Hadin village in the Auyo local government area when it capsized in the Kwalgai River, Lawan Shiisu, spokesman for the police in Jigawa, told reporters Monday.

At least two people were killed and 18 others were rescued, said Shiisu.

Citing a preliminary investigation, Shiisu said the incident was caused by "powerful waves and overloading to the extent where the driver was unable to steer the canoe."