SEOUL, South Korea (AP) — Asian stocks shuddered again Thursday, led by sharp drops in Hong Kong and South Korea, which were catching up to global market turmoil after being shut for Lunar New Year holidays.

KEEPING SCORE: Hong Kong's Hang Seng fell 4 percent to 18,526.03 after opening as much as 5 percent lower. South Korea's Kospi dropped 2.8 percent to 1,863.32. The Hong Kong and South Korean markets opened for the first time this week after Lunar New Year holidays. China and Taiwan will reopen on Monday. Japan was closed Thursday for a separate public holiday. Australia's S&P/ASX 200 was up 0.7 percent to 4,806.60. Singapore and New Zealand fell while benchmarks in the Philippines and Indonesia rose.

ANALYST'S TAKE: "What started in January as mainly China based worries has clearly broadened back out to concerns about global growth," said Shane Oliver, chief economist at AMP Capital in Sydney, Australia. He said five fault lines are driving concerns about the global economy: the malaise in emerging markets, the ongoing concerns about waning growth China, the collapse in oil prices, the strong dollar and fears that the global economy could plunge into a recession because of financial market turmoil.

YELLEN REMARKS: Federal Reserve Chair Janet Yellen offered no major surprises in prepared remarks released before the start of her two-day Congressional testimony. She reiterated the Fed's confidence that the U.S. economy was on track for stronger growth and a rebound in inflation. At the same time, she cautioned that global weakness and falling financial markets could depress the U.S. economy's growth. That would, in turn, slow the pace of Fed interest rate hikes, she said.

WALL STREET: U.S. stock markets opened with a rally but finished lower on Wednesday. The Dow fell 99.64 points, or 0.6 percent, to 15,914.74. The S&P 500 index slipped 0.35 point, or 0.02 percent, to 1,851.86. The Nasdaq added 14.83 points, or 0.4 percent, to 4,283.59.

ENERGY: Benchmark U.S. crude was down 53 cents to $26.92 a barrel in electronic trading on the New York Mercantile Exchange. The contract lost 49 cents, or 1.8 percent, to close at $27.45 a barrel on Wednesday in New York. Brent crude, a benchmark for international oils, dropped 31 cents to $30.53 a barrel in London.

CURRENCIES: The dollar weakened to 112.65 yen from 113.35 yen the previous day. The euro strengthened to $1.1293 from $1.1282.