Photo: AFP

Tokyo's key Nikkei stocks index opened higher but immediately drifted lower Monday, as investors waited for the results of an emergency policy meeting at the Bank of Japan later in the day.

The Nikkei 225 index lost 0.68 percent or 117.75 points to 17,313.30 in the first few minutes of trade while the broader Topix index was down 0.31 percent or 3.87 points at 1,257.83.