"Cereals inflation further firmed up to 6.3 per cent in June from 4.6 per cent in May 2016, which is a cause of worry," the rating agency said in a statement.
Although monsoon is likely to be above normal this year, there was some delay in monsoon showers reaching many parts of the country and that delayed the sowing of the kharif crops.
"It is, however, difficult to say whether the escalation in cereals prices is a temporary response to this delayed sowing or there is something else that has led to the sudden spike in the prices of cereals.
Food Corporation of India, the government's nodal agency to procure and distribution of foodgrains, held over 50 million tonnes of wheat and rice in its stock last month.
Food inflation rose to 8.18 per cent in June from 7.88 per cent in May and has nearly doubled from March 2016 (4.09 per cent). Like retail food inflation, cereals have emerged as a new driver of food inflation besides pulses and vegetables.
"Although moderation in pulses inflation could bring some relief to upside pressures on food inflation, a significant fall in pulses prices is unlikely since prices are driven by the supply-demand gap rather than seasonal factors," the agency said.
Fruit and vegetable prices rose sharply to 11 per cent in June from 7.7 per cent in May 2016, mainly led by vegetables.
Vegetable prices rose to 16.9 per cent and fruit prices increased to 6 per cent in June 2016 from 12.9 per cent and 3.8 per cent, respectively, in the previous month.
"Unlike cereals, intervention by the government to effect a softening in the prices of pulses and vegetable is not possible," the agency said.
"Management of food inflation will remain a challenge as price shocks emanating from the aberration in the prices of select agricultural commodities cannot be ruled out coupled with the demand-supply gap and inadequate agricultural supply chain infrastructure," India-Rating said.