The widespread decline came amid escalating tensions between Russia and Ukraine, with reports suggesting that the former is increasing its military presence near the Ukrainian border, according to CNN. Rumors of the troop buildup are as yet unconfirmed. Meanwhile, markets had already been suffering of late after Argentina’s second default in 13 years as well as concerns that the U.S. Federal Reserve could hike up interest rates sooner than expected.

With its latest massive drop-off, the Dow is now more than 720 points below the intraday record high it established in mid-July. The Dow dipped 0.8% on Tuesday, while the S&P 500 fell nearly 1% and the Nasdaq finished down nearly 0.7%.

The Chicago Board Options Exchange Volatility Index (VIX), often referred to as the “fear index,” rose nearly 10% on the day.

Last week, the S&P 500 saw its worst five-day decline since 2012 as the index lost 2.7% during that span. The Dow fell 2.7% last week, including a loss of 317 points last Thursday alone, while the Nasdaq dropped 2.2% over the course of the week. The three blue-chip indices had actually rebounded briefly to start this week, with the Dow rising more than 75 points on Monday, or 0.5%, and both the S&P 500 and Nasdaq rising 0.7% on the day.

The energy industry was among those hardest hit Tuesday afternoon, as has been the case since the U.S. and Europe hit Russia with the latest round of sanctions targeting the country’s energy, finance and defense sectors. Exxon Mobil (XOM) dipped 1.9% on Tuesday while oilfield services company Halliburton (HAL) declined 3.4%. Chevron (CVX), which signed a $10 billion shale gas deal with Ukraine last fall, saw its shares drop 2.5%.

Target (TGT) also fell 4.4% on Tuesday after the retailer lowered its second-quarter earnings forecast and also announced that it will book $148 million in expenses in the quarter due to a flood of claims over the massive data breach at the company last year.