Benchmark indices Sensex and Nifty tumbled in early trade on Wednesday amid renewed US-Iran tensions and a fresh spike in crude oil prices.

The 30-share BSE Sensex tanked 537.83 points to 77,642.89 in early trade. The 50-share NSE Nifty was down 163.55 points to 24,235.15.

From the Sensex pack, Asian Paints, InterGlobe Aviation, Reliance Industries, ITC, Bajaj Finance and Mahindra & Mahindra were among the major laggards.

Sun Pharma, HCL Tech, Tech Mahindra, Power Grid and ICICI Bank were the gainers.

Brent crude, the global oil benchmark, quoted 2.55 per cent higher at USD 76.05 per barrel.

"With the renewed US-Iran tensions and the consequent spike in Brent crude to USD 76, the market is again back to uncertain territory. How long this would last and what would be its consequences are now in the realm of uncertainty," VK Vijayakumar, Chief Investment Strategist, Geojit Investments Limited, said.

The market was slowly gaining strength on positive FII activity and improving macro fundamentals, he said.

"The renewed US- Iran tensions have put a temporary question mark on this positive development," Vijayakumar added.

In Asian markets, South Korea's Kospi and Japan's Nikkei 225 index traded lower, while Shanghai's SSE Composite index and Hong Kong's Hang Seng index were quoting higher.

US markets ended lower on Tuesday.

Foreign Institutional Investors (FIIs) bought equities worth Rs 393.19 crore on Tuesday, according to exchange data.

On Tuesday, fag-end selling dragged the Sensex lower, leading the benchmark to settle 104.35 points, or 0.13 per cent, down at 78,180.72. The Nifty dipped 31.65 points, or 0.13 per cent, to end at 24,398.70.

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