The Pew Research Center poll found 62 percent of respondents say social media companies have excessive control over news.

This results in a less favorable mix of news, 55 percent of respondents told the researchers.

Republicans tended to be more negative than Democrats about social media, with three-fourths of Republicans and Republican-leaning independents saying social media companies have too much control of news compared with 53 percent of Democrats and Democratic leaners.

The survey highlights rising worries about how social media shape the information people see online, and complaints from some -- including President Donald Trump -- that platforms are biased.

It comes as Facebook -- by far the most popular social network -- is set to release a news "tab" that will include content from a variety of news organizations.

The Pew survey indicated that the trend of people turning to social media for news continues to grow -- 55 percent of US adults said they get news from social media often or sometimes, up from 47 percent in 2018.

According to Pew, about half of all US adults get news from Facebook, with YouTube the second most popular at 28 percent, followed by Twitter (17 percent), Instagram (14 percent) and smaller numbers from services such as LinkedIn, Reddit and Snapchat.

The poll found more than 80 percent of respondents believe social media sites treat some news organizations differently than others.

Among those who say the platforms are partial, the vast majority said greater exposure was given to news organizations that produce "attention-grabbing articles," those with a high number of social media followers or those whose coverage has a certain political stance.

Roughly half of those critical of social media said they often showed inaccurate or one-sided news, while 35 percent said censorship of the news is a big problem on these sites.