A new video that shows the kidnapped in Gaza BBC correspondent Alan Johnston, dressed in an explosive vest has appeared on the Internet in the early hours of Monday.
It was posted by the Palestinian group, called Army of Islam that claims it is holding the reporter.
"The situation now is very serious. As you can see I have been dressed in what is an explosive belt, which the kidnappers say will be detonated if there was any attempt to storm this area," Johnston says in the video.
He appeals for a peaceful resolution to his situation, saying talks had reached an advanced stage.
The first video, which appeared on the Internet on June 1, showed the reporter in good health saying he had been treated "very well".
The captors' demands are for releasing of Abu Qatada, a Palestinian-born Islamic cleric who is supposed to have close links to al-Qaeda and is currently held by the UK government.
Alan Johnston was abducted from his car by four masked gunmen in Gaza about 3 months ago.
As he was being taken, the journalist threw a business card on the street that identified him as Alan Johnston of the BBC.
He has been reporting from Gaza for the past three years.