Higher petrol costs drove up US consumer prices in September for the second month in a row.

But outside energy, there was little sign of inflation last month.

The Labor Department said today that the consumer price index rose a seasonally adjusted 0.6% in September, matching the August increase.

In the past 12 months, prices have increased 2% - in line with the Federal Reserve's inflation target.

US food prices rose only 0.1% with the cost of meat, chicken and eggs falling while dairy prices rose. Excluding volatile food and energy costs, prices rose just 0.1%.

In the past year, so-called core prices have increased 2%. Lower inflation rates leave consumers with more money to spend, which can boost growth. Low inflation also allows the Federal Reserve to continue with its efforts to rekindle the economy. If the Fed were worried that prices are rising too fast, it might have to raise interest rates.

Petrol prices rose sharply over the summer and into September, but have since come down. But the summer's drought in the Midwest could ultimately affect grocery prices.

The drought caused spikes in the cost of corn, soybeans and other grains. Those grains are used in animal feed, which pushes up the price of chicken, beef and pork. And corn is also used in most products found throughout the supermarket, from cereals to soft drinks to cosmetics.

The economy remains the top issues for voters with just three weeks left before Election Day. However, recent data suggests consumers are gaining confidence in the economy. US consumer sentiment rose to a five-year high in October, according to a survey by the University of Michigan. And Americans stepping up their spending at retail businesses in September for the second month in a row, buying more cars and iPhones.

The job market is also looking a little better. The unemployment rate fell to 7.8% last month, the first time the rate has been below 8% since January 2009. And employers added an average of 146,000 jobs a month in the July-September quarter - double the average number created during the April-June quarter. Still, job growth remains too weak to rapidly bring relief to the more than 12 million Americans who are unemployed.

Last month, the Federal Reserve said it would try and stimulate the economy with a pair of bold steps. It is purchasing mortgage bonds to try and lower long-term interest rates and make home-buying more affordable. And it plans to keep short-term interest rates low even after the economy accelerates.