Video purports to show British aid worker slain

BEIRUT -- A video has been posted online purporting to show the beheading by the Islamic State group of British aid worker David Haines, who went missing in Syria last year.

The video emerged hours after the family of Haines issued a public plea on Saturday urging his captors to contact them.

Islamic State militants have beheaded two American journalists and posted video evidence online. At the end of the last video showing the beheading of Steven Sotloff, they threatened to kill Haines next and briefly showed him on camera.

The 44-year-old Haines was abducted in Syria in 2013 while working for an international aid agency.

The British government had managed to keep his kidnapping secret out of concern for his safety until the most recent video identified him as a captive.