OTTAWA (Reuters) - Canada's annual inflation rate in August jumped to 4.0% from 3.3% in July on higher gasoline prices, data showed on Tuesday, a sign the central bank may be forced to raise interest rates yet again after 10 hikes since March of last year.

Analysts polled by Reuters had forecast that inflation would hit 3.8%. The consumer price index rose 0.4% on a month-over-month basis in August, Statistics Canada said, compared with a predicted 0.3% gain. Two of the three core inflation measures also rose.

The annual rate, the highest since the 4.4% reported in April, is double the Bank of Canada's 2% target. The main driver was a 0.8% year-on-year increase in gasoline prices, which had dropped 12.9% in the 12 months to July.

"We have got to avoid overly strident opinions that the bank is done with rate hikes and be more circumspect, follow the evidence," said Derek Holt, vice president of capital markets economics at Scotiabank. "I still think we need to leave the door very much open to further rate hikes, plural."

Holt highlighted gains in two of the Bank of Canada's three core measures of underlying inflation - CPI-median edged up to 4.1% from 3.9% in July while CPI-trim rose to 3.9% from 3.6%.

Money markets raised bets for a rate hike in October after the data, seeing a 42% chance of an increase after the price figures compared with 23% before.

The Canadian dollar was trading 0.6% higher at 1.34 to the greenback, or 74.63 U.S. cents, after touching its strongest level since Aug. 10 at 1.3383.

However, another inflation report and a bevy of other data are due out before the Canadian central bank next meets on Oct 25 to set the key overnight rate.

"We still think the chance of a rate hike is low as we feel that they have stopped with the cycle," said Jimmy Jean, chief economist at Desjardins Group. "The economy is slowing and the unemployment numbers seem to be inching high, so those are important things that matter."