The Charleston Courier and Post apologized for sticking a gun advertisement on Thursday's front page. It covered part of the headline about deadly church shooting.
"The front-page sticky note that was attached to some home delivery newspapers on the same day as this tragedy is a deeply regrettable coincidence. We apologize to those who were offended," the newspaper said in a statement.
Police arrested 21-year-old Dylan Roof for allegedly opening fire during a Wednesday night prayer meeting at the Emanuel AME Church in downtown Charleston.
Nine people were killed, including the Rev. Clements Pinckney, a South Carolina state senator and pastor at the historically black church.
Journalist Jim Romenesko wrote in his blog that an advertising manager at the newspaper said it was "unfortunate timing" on a scheduled ad.
Romenesko pointed out that it could have been removed and rescheduled.