The gap between black and white Americans over whether race relations is the biggest US problem is wider than it has been in any year since the period from 2002 to 2007, a survey released on Thursday showed.
The Gallup survey comes after a series of police killings of unarmed black men in Ferguson, Missouri, New York's Staten Island, and Baltimore, Maryland, have fueled a national debate about justice for US minorities.
After weeks of protests over the August 2014 death of 18-year-old Michael Brown, in Ferguson, blacks became just as likely to name race relations as the nation's top problem as they were to name unemployment, the polling company found.
In the last quarter of 2014, 15 percent of blacks cited race relations as the top US problem, compared with 3 percent of whites in the same quarter - a 12 percent gap, the survey found.
In the most recent quarter - April to June 2015 - the gap was 9 percentage points - 13 percent of blacks and 4 percent of whites named race relations as the most important US problem.
The gap was no more than four percentage points in any year from 2002 to 2007, Gallup reported.
At the start of 2014, 3 percent of black Americans and 1 percent of white Americans mentioned race relations as the most important US problem.
Among all Americans sharing that opinion, the amount increased from 1 percent to 5 percent from the first to fourth quarters of 2014 to a 4 percent to 5 percent range for 2015, the survey said.
The findings are based on six quarters of Gallup's monthly measurement of the "most important problem" question from January 2014 through June 2015.
Gallup said it conducted telephone interviews from April through June 2015 across a random sample of 3,566 adults, ages 18 and up, in all 50 U.S. states and the District of Columbia.
The margin of error was plus or minus 2 percentage points at the 95 percent confidence level, Gallup said.