A Palestinian Cabinet minister said Friday there were the "first promising signs" in the case of two FOX News journalists abducted in Gaza nearly two weeks ago.

"Efforts and contacts are being made to guarantee the safety and bring about the release of the two guests of Palestine," said Interior Minister Said Siyam of Hamas, speaking to reporters outside a Gaza mosque.

"There are first promising signs," Siyam said, without elaborating.

Palestinian Prime Minister Ismail Haniyeh of Hamas said winning their release is at the top of his agenda. "I have appealed to the kidnappers not to harm the journalists and to release them immediately," he added.

Security officials said they still had not made contact with those behind the abductions.

A previously unknown group calling itself the Holy Jihad Brigades is demanding the release of all Muslims held by the U.S. by midnight Saturday, in exchange for the two journalists, who were abducted Aug. 14. It is not clear whether the kidnappers are local militants, either with ties to Hamas or the rival Fatah movement, or sneaked into Gaza from outside.

The group did not say what it would do if the prisoners were not released.

On Friday, civil rights leader the Rev. Jesse Jackson appealed for the two men to be released.

"They are in a crisis they did not create. They should not be kept as trophies and we appeal for their release," Jackson told New Zealand television network TV3.

Jackson was to lead an ecumenical delegation to the Middle East this weekend to meet with political and religious leaders about the kidnapping and other developments in the region, including the capture of three Israeli soldiers by Islamic militants.

"Please release them because to release them is to open up a door of opportunity for more meaningful dialogue. The same is true of the three Israeli soldiers ... and of course, there are Lebanese and Palestinians who are in prison as well," he said.

Siyam's and Hamas' statements come a day after families of the two journalists issued pleas for their safe return.

"Our brother and his colleague are in Gaza to report your story," said Ken Centanni, brother of kidnapped reporter Steve Centanni, in a taped message released Thursday. "Nothing more and nothing less. It is in your control to resolve this matter. I respectfully request that you let our brother Steve and his colleague come home to their families."

"People should not be kept from their families," said Anita McNaught, wife of kidmapped cameraman Olaf Wiig, reading a statement Thursday after meeting with Palestinian Prime Minister Ismail Haniyeh.

"In the name of the Muslim values and traditions you so strongly uphold, these two men are your guests. We all desire a peaceful resolution of this matter — for us and for you. We want our men to come home safe," McNaught said.

Click here to read the full text of both statements.

On Wednesday, the kidnappers released video of the hostages for the first time. Wearing track suits, Centanni and Wiig are seen sitting cross-legged on the floor of a dark apartment. They said they were being treated well.

The Associated Press contributed to this story.