The CPI rose 1.68% in September year-on-year, the most in four months, compared with a forecast for a rise of 0.70% in a Reuters poll. It followed August's 0.02% dip.

October's CPI is expected to be similar to September's pace, ministry official Wichanun Niwatjinda told a news conference on Thursday.

Consumer prices in the fourth quarter are likely to increase further, driven by higher oil prices, improved economic activity after the easing of coronavirus restrictions and a weaker baht currency, he said.

"Our inflation is not high like other countries because of government support measures," he said, adding main inflation was expected at 0.8% to 1.2% this year, barring additional government measures to reduce living costs.

In September, the core CPI index was up 0.19% from a year earlier, compared with a forecast for a 0.20% rise.

In the January-September period, headline CPI rose 0.83% from a year earlier, with the core rate up 0.23%.

(Reporting by Orathai Sriring and Kitiphong Thaichareon; Editing by Martin Petty)