China’s key mainland stock markets have suffered their sharpest falls in three weeks overnight as the latest batch of economic statistics indicate China’s economy continues to weaken.

Both the Shanghai and Shenzhen markets were more than 3.5% lower this morning.

According to figures published over the weekend, Chinese investment grew at its slowest pace in 15 years in the first eight months of the year to date – though it is still robust at 10.9%.

Industrial output was also weaker than expected, rising by 6.1% in the year to August, compared with an expected increase of 6.6%.

Investments in non-rural areas in China rose by 10.9% between January and August - this was down from the 11.2% increase recorded between January and July.

The country is set to struggle to meet its target of 7% growth for 2015.

This is a critical week for interest rates, with the Federal Reserve Policy Committee meeting on Wed an Thurs and perhaps deciding to raise US base interest rates for the first time in nine years.