Geopolitical concerns grew after Israel's suspected killing of Iranian generals in Damascus earlier this week raised the prospect of potential retaliation by Iran, with Prime Minister Benjamin Netanyahu vowing to defend the country if attacks occur. Market players were also cautious ahead of a key monthly U.S. jobs data release for March that could reveal clues on the timing of possible interest rate cuts, after some Federal Reserve officials suggested that rate cuts might not be imminent. The 225-issue Nikkei Stock Average index plummeted 781.06 points, or 1.96%, to finish at 38,992.08. The broader Topix index of all First Section issues on the Tokyo Stock Exchange retreated 29.38 points, 1.08%, to 2,702.62. Total 25 of 33 TSE sectors closed lower, with precision Instruments, down 3.2%, followed by Securities & Commodities Futures (down 2.5%), Electric Appliances (down2.4%), Machinery (down 2%), and Electric Power & Gas (down 1.68%) sectors, while Textiles & Apparels ..