The CPI in the first five months of this year increased by 1.59 percent on an annual basis, the office said.
Among the 11 groups of products and services, transportation services posted the highest growth in May with 2.39 percent; building materials followed with 0.88 percent; goods and other services ran third with 0.56 percent.
The other 8 groups made slight increases, of which restaurant and catering services added up 0.36 percent.
The May CPI rise was attributed to an increase of 0.68 percent in food price caused by drought and saltwater intrusion in the Mekong Delta as well as rice purchases made by traders to fulfill their export contracts. By mid-May, the price of rice dropped as Thailand announced that it would release 11.4 million tons of stockpiled rice in May and June this year. However, in comparison with the same period last year, rice price was still about VND300 per kilogram higher.
Petrol hike on April 20 and May 5 led to a surge of 5.15 percent in fuel prices over the previous month, contributing an increase of 0.21 percent to general CPI rise.
Building material prices gained 0.37 percent due to increasing building demand along with a rising trend in global input building material prices.
Gas prices jumped 2.44 percent as gas companies raised their prices by VND5,000 per 12-kilogram tank since May 1 as global gas prices escalated.
The price of health insurance services hiked 4.72 percent as the State rose the minimum wage from VND1.15 million per month to VND1.21 million per month from May 1.