Palestinian militants today demanded the release of Muslim prisoners from American jails in return for the freeing of two Fox News journalists who were kidnapped in Gaza earlier this month.

The demand was made in a video showing the two men, Steve Centanni, an American correspondent, and Olaf Wiig, a cameraman from New Zealand, that was aired today by the Arabic news network Al Jazeera. It was first sign that the men were alive since they were bundled from their TV van near the Palestinian security services headquarters in Gaza City on August 14.

The kidnapping of the two men, claimed by a previously unheard-of group, the Holy Jihad Brigades, has confused security officials in the Palestinian territories because it has not followed the pattern typical of local militants.

Although westerners are frequently taken hostage in the territories, demands are very rarely made of foreign governments, and hostages are not ordinarily held for this long. Today's video also carried many of the characteristics of recent kidnappings in Iraq, including heavily religious language and the use of a hitherto unknown militant faction.

Palestinian government officials, including the Prime Minister, Ismail Haniya, have called for the release of the two men, but to no avail. Today's was the first claim of responsibility for their capture.

In the video, which showed Mr Centanni, who is 60, and Mr Wiig, 35, wearing sweatshirts and sitting on the floor against a black background, the two men said they were being treated well. Mr Centanni said they had access to water, food and a bathroom with a shower.

"We’re in fairly good condition, we’re alive and well, in fairly good health," he said. "Just want to let you know I’m here and alive and give my love to my family and friends and ask you to do anything you can to try to help us get out of here."

Mr Wiig said he believed that efforts were already being made on the men's behalf but added: "If you could apply any pressure on the local government here in Gaza and the West Bank that would be much appreciated by Steve and myself."

The accompanying demand from the Holy Jihad Brigades did not specify whether it meant for the US to free Muslim prisoners held at Guantanamo Bay or abroad or at American prisons in general. Neither did the note say what would happen to the journalists if the three-day deadline set by the group passed without its demands being met.

"We are going to exchange the Muslim female and male prisoners in American jails in return for the prisoners that we have. We are going to give you 72 hours, beginning midnight tonight, to take your decision," the statement said.

"If you implement and meet our condition, we will fulfill our promise. If not, wait, and we are going to wait with you."

Times Recommends

• Experts baffled by vanishing sea lions
• CIA caught in a dirty and secretive war
• Double life of Umar Farouk Abdulmutallab