Signs that the US economic recovery is gaining momentum have come from the latest Commerce Department figures which show retail sales increased for the tenth month in a row in April.

According to the data, total sales were 0.5% than in March at $389.4bn, and were 7.8% higher than April last year. Retail trade sales were up 0.6% on March, and 7.9% above last year.

Sales at clothing and clothing accessory stores edged up 0.3% month-on-month and were up 8.6% year-over-year, helped by this year's late Easter holiday. But sales at department stores slipped by 0.2% from March, and were flat with last April.

Despite the overall gains, observers warn the numbers are modest compared with previous months - and that this is evidence some consumers are beginning to feel the strain of high food and gas prices.

"With ten consecutive months of growth, retailers are on the front lines of economic recovery, though higher commodity prices are beginning to weigh on some consumers," noted Matthew Shay, president and CEO of the National Retail Federation (NRF).

"Positive economic indicators such as increases in job openings and wage growth are certainly helping boost consumers' confidence, and support spending," added NRF chief economist Jack Kleinhenz.

"While there are reasons to be optimistic, plenty of other concerns exist which could very easily shift consumers' spending habits, including decreasing home prices, high unemployment levels and rising costs at the pump."