NEW YORK (CNN) - Holiday shoppers continued their trek to malls and big-box stores Saturday, amid early indications of slightly higher Black Friday sales to kick off the season.

The nation's retailers were watching anxiously, having already suffered significant declines this year thanks to the weakening U.S. economy.

But the first nationwide returns were positive for merchants.

One Research firm says Black Friday sales are up 3%, thanks to deep discounts, in cautious start to the season.

ShopperTrak RCT, a retail industry research firm, said total Black Friday sales rose 3% this year, to about $10.6 billion nationwide.

Bill Martin, the firm's co-founder, said that given the headwinds facing the nation's merchants - a troubled economy, the traditional weakness in a presidential election year and the aftermath of the summer's record gas prices - the first day was pretty positive.

"Under these circumstances, to start off the season in this fashion is truly amazing and is a testament to the resiliency of the American consumer, and undeniably proves a willingness to spend," Martin said in a statement.

He credited deep discounting for a lot of the sales increases, which were fairly consistent across the nation - up 3.4% in the South, 3% in the Midwest, 2.7% in the West and 2.6% in the Northeast.

"While this is an encouraging start for retailers, there's no guarantee these deep discounts will continue after Black Friday weekend, which could slow spending," said Martin. "Additionally, consumers have just 27 days to shop this year as opposed to 32 in 2007, which may catch some procrastinating consumers off guard, leading to lower sales levels."