The rupee today plunged by 29 paise or 0.44 per cent to close at a six-month low of 65.49 against the US currency on widening trade deficit concerns amid heightened geopolitical worries.
The Indian unit was the biggest loser among Asian currencies which suffered due to a strong US dollar after the strike on Syria by the US, the UK and France.
Among Asian currencies, Chinese yuan and Singapore dollar dropped 0.1 per cent, the Philippine peso and Malaysia's ringgit declined up to 0.2 per cent against the dollar following hopes that the strikes would not lead to a broader escalation in the conflict.
The rupee resumed on a bearish note at 65.30 per dollar from previous close of 65.20 at the inter-bank foreign exchange (forex) market.
After trading in a narrow range during the early part of the day, the home currency drifted sharply in mid-afternoon deals to hit a fresh intra-day low of 65.51 before concluding the day at 65.49, revealing a steep loss of 29 paise, or 0.44 per cent.
This is the lowest closing since October 3, 2017, when it had settled at 65.50 against the US dollar.
The US Treasury Department added India to its watch list of countries with potentially questionable foreign exchange policies, joining China and four others which impacted overall forex trading mood, traders said.
The twin shocks of country's trade deficit hitting USD 13.69 billion and exports dipping after a gap of four months in March weighed on the rupee.
Capital outflows too added pressure even as importers rushed to cover their unhedged positions.
According to exchange data, foreign investors withdrew Rs 308.13 crore from capital markets today.
On the global energy front, crude oil prices edged higher after last week's bullish surge as the markets became more relaxed about Syria and eyed more production increases in the US.
Brent crude, an international benchmark, was trading marginally higher at USD 71.82 a barrel in early Asian trade.
The RBI, meanwhile, fixed the reference rate for the dollar at 65.4476 and for the euro at 80.7362.
Meanwhile, domestic stocks continued their winning run for the eighth straight session on the back of improving macroeconomic conditions as well as optimism about upcoming corporate earnings season.
The dollar index, which measures the greenback's value against a basket of six major currencies, was up 0.1 per cent at 89.850.
In the cross currency trade, the rupee continued its downtrend against the pound sterling and settled sharply lower at 93.68 from 92.97 last weekend.
The local unit also retreated against the euro to end at 81.00 from 80.31 and also fell back against the Japanese yen to finish at 61.06 per yens from 60.55.
In the forward market today, premium for dollar edged lower due to mild receiving from exporters.The benchmark six-month forward premium payable in August eased to 94.50-96.50 from 95.50-97.50 paise and the far-forward February 2019 contract also moved down to 215-217 paise from 216-50-218.50 paise previously.