Chinese manufacturing showed further signs of weakness in August, adding to evidence of an inexorable slowdown in the world's No. 2 economy.

Two factory activity indexes released Tuesday were at multi-year lows.

An official manufacturing index based on a survey of factory purchasing managers fell to a three-year low of 49.7 in August from 50.0 in July, based on a 100-point scale on which numbers above 50 indicate expansion.

The index compiled by the Chinese Federation for Logistics and Purchasing is at its lowest level since August 2012.

A separate survey, the Caixin purchasing managers' index, fell to a six-year low of 47.3 from 47.8 in July.

The number was slightly better than a preliminary reading released last month.

The dismal data on China's manufacturing industry, which employs tens of millions of people, adds to concerns over the country's financial and economic health.

In the latest attempt to shore up flagging economic growth, China's communist leaders cut interest rates last week, the fifth time they have done so in nine months.

The rate cut had been expected after recent economic indicators such as exports were weaker than expected.