China's two stock markets both fell more than 3 per cent on Friday, as analysts said investors were worried that the government planned to raise interest rates and introduce other measures to cool the country's rampant economic growth, according to dpa. The key Shanghai Composite Index closed at 4,091.45, down 139.38 points or 3.29 per cent, after slumping to a low of 4.87 per cent down in a day of strong fluctuations. The fall was the largest since June 4 and came amid "wide-spread anticipation of further tightening monetary measures" this weekend, the official Xinhua news agency said. The smaller Shenzhen Component Index ended Friday at 13,725.72 points, losing 3.72 per cent. Concern has also mounted this week about the overexpansion of the Chinese markets amid a number of large upcoming public offerings.