After a week of being behind Hillary Clinton by ten points or more in various polls, Donald Trump has suddenly pulled to nearly even in a national poll by Reuters/Ipsos released Saturday.

Clinton leads with 42 percent of the vote compared to 39 percent for Trump, a significant gain for the GOP nominee, who had been behind by eight points in a Reuters poll Monday.

"The reasons behind the shift were unclear," Reuters said.

The survey was conducted July 31 to August 4 as controversy raged over Trump's response to a Muslim couple, Khizr and Ghazala Khan, who spoke out against the Republican during the Democratic National Convention. Their son had died fighting in Iraq. Trump questioned why Ghazala Khan didn't speak, insinuating she was prevented from doing so because she is Muslim.

The online poll of 1,154 likely voters had a margin of error of plus or minus 3 points, Reuters said.