AMSTERDAM - Twitter is trying to block the spread of gruesome images of the apparent beheading of journalist James Foley by Islamic State militants, while a movement to deny his killers the publicity they crave is also gaining momentum.

In a tweet published late Tuesday California time, CEO Dick Costolo said his company "is actively suspending accounts as we discover them related to this graphic imagery," and he gave a link to a New York Times story about Foley's killing.

advertisement | advertise on newsday

Twitter spokesman Nu Wexler confirmed Costolo's tweet and referred further questions to a company policy page. Twitter allows immediate family members of someone who dies to request image removals, although the company weighs public interest against privacy concerns. Foley's parents have confirmed that he is the man in the video. The U.S. government is trying to confirm the death.

Twitter users who oppose spreading the images are using the trending hashtag #ISISMediaBlackout.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.