BEIJING -- The volume of freight carried on China's railways picked up slightly in May amid continued weakness in the world's second-largest economy.

Railways transported 283.84 million tons of cargo in May, up 2.73 percent from the previous month, according to statistics from the China Railway Corporation.

In the first five months, total rail freight volume amounted to 1.43 billion tons, the data showed.

The lukewarm data added to a slew of other indicators showing continued weakness in the economy.

Data on Monday showed China's exports slipped 2.8 percent year on year to 1.17 trillion yuan ($191.16 billion) last month, while imports slumped 18.1 percent from a year ago to 803.33 billion yuan.

Dragged down by a housing slowdown, softening domestic demand and unsteady exports, China's economy in 2014 grew 7.4 percent, its weakest annual expansion in 24 years. GDP growth in the first quarter of the year eased to 7 percent.

Given the prolonged weakness, HSBC earlier cut its forecast for China's 2015 GDP growth to 7.1 percent from 7.3 percent.