China's official Purchasing Managers' Index rose to 53.3 in April, suggesting business activity in the manufacturing sector expanded for a fifth month.

The index, which was released by the China Federation of Logistics and Purchasing on Tuesday, picked up 0.2 points from that of the previous month. The gauge also stayed above the level in the same period last year, and has registered the highest reading in 12 months.

A PMI reading above 50 indicates expansion of the manufacturing sector while a figure below that mark shows a contraction.

Among the sub-indices, "large and medium-sized companies" at 53.7 were a main driver for the overall increase in April, while the "small companies" gauge plunged below 50 for the first time in four months to 49.1.

The measure of output sub-index rose to 57.2 in April from 55.2 the previous month, the highest since Jan 2011, according to the federation.

The new orders index at 54.5 was increasing at a slower pace while export orders at 52.2 gained at a faster rate than the previous month, the data showed.

The figures signal China may be strengthening from the slowest pace of economic growth in almost three years reached in the first quarter this year, reducing pressure on policy makers to open the taps on credit.