TOKYO: Tokyo stocks slumped and oil prices rose on Tuesday after Russian President Vladimir Putin ordered his troops into two Moscow-backed rebel regions of Ukraine.
The benchmark Nikkei 225 index was down 1.46 percent or 391.72 points at 26,519.15 around 30 minutes after the opening bell, dipping more than two percent.
The broader Topix index was down 1.10 percent or 21.02 points at 1,889.66.
The dollar bought 114.67 yen -- seen as a safe-haven currency -- in early Asian trade, firming from 114.82 yen in London late Monday.
Oil prices spiked, with WTI up 3.14 percent to $93.93 per barrel and Brent North Sea gaining 1.98 percent to $95.39 per barrel.
In a move that could set off a potentially catastrophic war with Kyiv, Putin ordered Russia's military to act as peacekeepers in two breakaway regions of Ukraine, just hours after he recognised them as independent.
Investors in Tokyo were spooked by Putin's announcement, which defied Western threats of sanctions.
Falls in the Japanese market were due to "intensifying tensions in Ukraine," Toshiyuki Kanayama, senior market analyst at Monex, said in a note.
US markets had been closed for a holiday on Monday.
Among shares in Tokyo, Nissan was down 3.28 percent at 578.5 yen, Uniqlo operator Fast Retailing was off 2.48 percent at 62,810 yen, and airline ANA Holdings was down 1.40 percent at 2,576 yen.
Daiichi Sankyo soared 9.86 percent to 2,801 yen after AstraZeneca reportedly said data from a late-stage trial showing its drug Enhertu -- which the Japanese drugmaker jointly develops -- helps patients with a type of breast cancer live longer, potentially expanding treatment options.