Canada's main stock index fell Tuesday, the first trading day after a long weekend, as investors pulled back amid tensions in the Korean Peninsula.

The Toronto Stock Exchange's benchmark Standard & Poor's/TSX Composite Index fell 101.45 points, or 0.67 percent, at 15,090.15. Eight of 10 main groups declined.

The most influential movers on the Canadian index included Royal Bank of Canada, which fell 1.34 Canadian dollars, or 1.5 percent, to 90.77 Canadian dollars, and insurer Manulife Financial went down 64 cents, or 2.6 percent, to 24.01 Canadian dollars.

Teck Resources Ltd dropped 6.7 percent to 29.47 Canadian dollars after Chinese sovereign wealth fund China Investment Corp, a cornerstone shareholder, sold a substantial chunk of its holding.

The energy group edged 0.4 percent higher as crude prices jumped and gasoline slumped with refineries in Texas starting to resume operations in the wake of Hurricane Harvey. Another hurricane, Irma, is rolling toward the southern United States.

Canadian Natural Resources rose 1.5 percent to 39.30 Canadian dollars after agreeing to buy Cenovus Energy's Pelican Lake heavy oil operations in Alberta for 975 million Canadian dollars. Cenovus shares surged 3.3 percent to 10.28 Canadian dollars.

The materials group, which includes precious and base metals miners and fertilizer companies, rallied 0.2 percent as gold miners were boosted by a jump in the precious metal to a one-year high, offsetting Teck's fall.

The Canadian dollar edged up 0.2 cents to 0.80.77 U.S. dollar while oil prices rallied 1.26 dollars to 48.55 U.S. dollars. Gold prices jumped 15.80 dollars to 1,346.20 U.S.dollars an ounce.