BEIJING, May 19 -- China's retail sales of consumer goods, a major indicator of the country's consumption strength, expanded 5.1 percent year on year in April, official data showed Monday.

Total retail sales of consumer goods reached 3.72 trillion yuan (about 517.27 billion U.S. dollars) last month, according to the National Bureau of Statistics (NBS).

Retail sales in the country's urban regions rose 5.2 percent year on year in April, while those in rural areas expanded 4.7 percent.

Driven by the government's consumer goods trade-in program, sales of home appliances and audio equipment surged by 38.8 percent last month, and sales of cultural and office goods jumped by 33.5 percent.

"In April, the combined retail sales of consumer goods related to trade-ins, including household appliances and audio-visual equipment, cultural and office supplies, furniture, communication equipment, and building and decoration materials, contributed to a 1.4 percentage point increase in the total retail sales of consumer goods," NBS spokesperson Fu Linghui said at a press conference.

From January to April, the retail sales of consumer goods rose 4.7 percent year on year, accelerating from the 4.6 percent growth in the first three months, according to the NBS.

China's online retail sales went up 7.7 percent year on year during the first four months, sustaining relatively fast growth.

"As the effects of pro-consumption policies continue to take hold and consumer momentum keeps growing, the role of consumption in driving economic growth is expected to further strengthen," Fu added.