BEIJING, Aug. 31 -- China's non-manufacturing activity continued to expand in August thanks to recovering services and a robust construction industry, official data showed Thursday.

The purchasing managers' index (PMI) for the non-manufacturing sector came in at 51 in August, according to the National Bureau of Statistics (NBS). The figure was 51.5 in July.

A reading above 50 indicates expansion, while a reading below it reflects contraction.

Senior NBS statistician Zhao Qinghe said the service sector sustained the recovery momentum in August boosted by consumption of summer vacation, and the construction industry also registered quicker expansion.

The sub-index for the service sector was 50.5 in August, in particular, business activities of transport, accommodation and catering stood well above 55 for two consecutive months.

The construction sector's sub-index was 53.8 this month, up from 51.2 in July. The optimism about the sector's prospects has remained high, NBS data showed.