Smartphones are bridging a US digital divide as minorities tap into the Internet using mobile devices, according to a Pew study released on Friday.

"Groups that have traditionally been on the other side of the digital divide in basic Internet access are using wireless connections to go online," the study concluded.

"African American and English-speaking Latinos are as likely as whites to own any sort of mobile phone, and are more likely to use their phones for a wider range of activities."

While race and gender were fading as obstacles to Internet access, matters changed when it came to age, education, and income, according to the study.

"Ultimately, neither race nor gender are themselves part of the story of digital differences in its current form," the study said.

"Instead, age (being 65 or older), a lack of a high school education, and having a low household income (less than $20,000 per year) are the strongest negative predictors for Internet use."

The findings, based on a survey conducted in the middle of last year, also found notably less Internet use by those who opted to respond in Spanish instead of English.

"Yet even groups that have persistently had the lowest access rates have still seen significant increases over the past decade," Pew researchers said.

One in five US adults do not use the Internet, with the most common reason being that they simply weren't interested, according to the study.