Canadians are being warned by the federal government about travelling to northern Mexico.

Foreign Affairs is advising Canadians not to travel to the border city of Ciudad Juárez.

Two Americans were shot to death in the city last weekend in shootings apparently linked to ongoing drug wars.

"Travellers are advised to reconsider their need to travel to Ciudad Juárez and should only do so if it is absolutely necessary," the Foreign Affairs department said on its web site.

More than 18,000 Mexicans have been killed in the drug conflict over the past three years.