WASHINGTON, Aug 19: One in five Americans believes that President Barack Obama is a Muslim, says a new survey released on Thursday.

Another poll, also by the Pew Research Centre, shows that plurality of whites continues to disapprove President Obama, 49 per cent, versus 38 per cent who approve.

More than a year and a half into his presidency, a plurality of the public says they do not know what religion Mr Obama follows.

They also refuse to believe the president's repeated and public statements about his Christian faith and disregard his attendance in church.

The view that Mr Obama is a Muslim is highest among his political opponents — 31 per cent of Republicans and 30 per cent of those who disapprove of his job performance express this view. It is lower among his supporters — 10 per cent among both Democrats and those who approve of his job performance.

The share of Republicans who say Mr Obama is a Muslim has nearly doubled over the past year and a half — from 17 per cent to 31 per cent.

The number of independent voters with the same mistaken belief has also risen, by eight points, to 18 per cent.

Meanwhile, the number of Americans who correctly identify Obama as a Christian has fallen by nearly half from a year ago, to 34 per cent.

The poll was taken before Obama waded into a bitter dispute last week over plans for a mosque and interfaith centres just blocks from the New York site of the Sept 11, 2001 attacks.

Mr Obama said on Friday he supported the right of Muslims to build a mosque near Ground Zero. Amid political backlash a day later, he said he was commenting on religious freedom, not the exact location of the mosque.

White House officials told reporters they believed that mistaken impressions about Mr Obama's faith were the result of “misinformation campaigns” by his opponents.

There is also a wide racial divide in the perception that Mr Obama is a Muslim. The number of whites who believe this rose from 11 per cent to 21 per cent since March 2009, while there has been virtually no change in blacks' views on this question — 7 per cent say Mr Obama is Muslim today, compared with 6 per cent in 2009.

But both blacks and whites are less likely today to say Mr Obama is a Christian. Of those who believe Mr Obama is Muslim, 60 per cent say they learned about his religion from the media.