British PM promises to defeat Islamic State

British Prime Minister David Cameron on Sunday praised slain British aid worker David Haines as a hero and pledged to continue working as part of an international coalition to "hunt down those responsible and bring them to justice no matter how long it takes," the Los Angeles Times reports on Sunday.

The militant group Islamic State released a video on Saturday purporting to show his beheading. Britain’s Foreign Office said the video appeared to be authentic.

Cameron added that Britain and the rest of the world cannot ignore the threat Islamic State poses.

“Step by step we must drive back, dismantle and ultimately destroy ISIL and what it stands for,” Cameron said. “They are not Muslims, they are monsters.”