US stocks Friday moved lower in early trade as a wave of selling pressure continued following a weak report on Chinese manufacturing activity. About 30 minutes into trade, the Dow Jones Industrial Average fell 98.51 points (0.61 percent) to 16,098.84. The broad-based S&P 500 dropped 13.28 (0.73 percent) to 1,815.18, while the tech-rich Nasdaq Composite Index declined 35.69 (0.85 percent) to 4,183.18. The sell-off followed steep declines Thursday after a report said Chinese manufacturing activity in January contracted for the first time in six months. European stock markets were also down sharply Friday following the report, which raised concerns about the world's second-biggest economy and one of its most important growth markets. Analysts also have attributed the Wall Street retreat to disappointment that US corporate earnings have not been better. "Uncertainty has gripped the market, and when uncertainty does that, there is a tendency to sell first and ask questions later, particularly when the market is coming off a quarter in which it gained 10 percent," said Briefing. com analyst Patrick O'Hare. Dow component Microsoft advanced 3.1 percent after reporting record revenues in its fiscal second quarter on the back of strong demand for Xbox consoles, Surface tablets and Internet "cloud" services. Fellow Dow member Procter & Gamble jumped 4.0 percent after earnings bested expectations by a penny at $1.21 per share. The company also confirmed its full-year forecast. Online vendor eBay dipped 1.8 percent after activist investor Carl Icahn vowed a proxy war over his proposal to spin off the company's PayPal unit. Juniper Networks, a software and network security company, leaped 8.2 percent following reports that activist investor Jana Partners took a stake in the company. US healthcare group McKesson rose 1.6 percent after announcing a deal to acquire German pharmaceuticals wholesaler Celesio. Bond prices rose. The yield on the 10-year US Treasury declined to 2.73 percent from 2.77 percent Thursday, while the 30-year fell to 3.65 percent from 3.68 percent. Bond prices and yields move inversely.