Vietnam's Consumer Price Index (CPI) is forecast to rise 2.2 percent in September over the previous month, making it the highest September index since 1995, and the highest month-on-month CPI growth since June 2011, according to a report by Vietnam's General Statistics Office (GSO) on Monday.

The country's CPI is expected to rise 6.48 percent year-on-year and 5.13 percent over last December.

Accordingly, all the 11 commodities posted increases between 0. 01 to 17.02 percent.

The group of medicine and healthcare hit the highest growth rate during the month, while postal and telecommunication group saw the lowest increase.

According to Nguyen Duc Thang, head of the Pricing Department under GSO, the sharp increase of September CPI is attributed to the price hike of essential goods and services including medicine and healthcare services, education, transportation, and housing and construction materials. These groups of commodities contributed up to 2.1 percent of the national CPI rise.

Housing-construction materials and education groups posted an increase of 2.18 percent and 10.54 percent respectively.

Although not included in the CPI calculation, during the month, the gold price increased 5.25 percent against that in August, and the U.S. dollar exchange rate increased 0.06 percent over the previous month.

September CPI in the two big cities of capital Hanoi and southern Ho Chi Minh City is forecast to increase sharply by 2.47 percent and 1.21 percent respectively, pushing up the overall national CPI.

According to Thang, after two consecutive months of deflation in June and July, and one month of 0.03 percent increase in August, the high September CPI triggered worries that inflation this year will climb higher than set target of 7 percent due to higher consumption demand in the last months of the year as well as credit easing and the late effects of the government's stimulus package earlier this year.