US stocks tumbled in opening trade Monday, dragged down by escalating tensions in Ukraine as the country verges on civil war and disappointing manufacturing data from China.
Shortly after the opening bell, the Dow Jones Industrial Average was down 120.79 points (0.73 percent) to 16,392.10.
The broad-based S&P 500 dropped 13.55 (0.72 percent) to 1,867.59, while the tech-rich Nasdaq Composite Index slumped 34.39 (0.83 percent) to 4,089.51.
Over the weekend, clashes between pro-Russian separatists and Ukraine loyalists heated up in eastern Ukraine and "ignited concerns about the prospect of a civil war," said Patrick O'Hare of Briefing.com.
"Those concerns, and worries about potential spillover effects, have weighed on European markets today and have helped exert some downward pressure" on Wall Street, he said.
Also weighing on sentiment was HSBC's worse-than-expected data on manufacturing in China, the world's second-largest economy, showing the sector contracted for a fourth consecutive month in April, analysts said.