Isis-linked 'countdown clock' reaches zero as 72-hour deadline to save hostages expires

Posting reportedly carried warning 'the countdown has begun'

Kenji Goto (L) and Haruna Yukawa (R) are being held hostage by Isis

A countdown clock allegedly posted by militants associated with Isis online has reached zero after a 72-hour ransom deadline expired, it has been reported.

The posting, which appeared on Friday, was initially posted with the warning: "the countdown has begun" along with gruesome images of other hostages who have been beheaded by the group, according to the Associated Press.

A video emerged on Tuesday showing a black-clad militant wielding a knife and threatening to execute Kenji Goto and Haruna Yukawa if the Japanese Government did not pay a $200 million (£132m) ransom within 72 hours.

Tokyo believes the deadline expired at 5.50am GMT on Friday, according to AFP.

Junko Ishido, the mother of 47-year-old journalist Mr Goto, made a tearful appeal on behalf of her son as the ransom deadline demanded by Isis for him and Mr Yukawa drew closer.