Sawaf Abu Saif was arrested early on Saturday, July 26, during a crackdown by the radical Islamic Palestinian movement on its rivals, including the moderate Fatah party of President Mahmoud Abbas.

The detentions in the Hamas-controlled Gaza Strip followed a series of bombings in and around Gaza City on Friday in which six people were killed. Hamas blames Fatah for the violence.

Hamas officials reportedly accuse Abu Saif of being a Fatah sympathizer. ARD had learned that he was in poor health, officials at the broadcaster's headquarters in Saarbruecken in south western Germany said.

Fears for journalist's well-being

ARD was "deeply concerned" about him, said ARD Chairman Fritz Raff, adding that under the circumstances, the work of journalists in Gaza was no longer possible.

"Everyone who works with him knows and says the allegations against him are baseless."

The broadcaster said that it would only reopen its Gaza office once its cameraman was able to return safely to his family.

Members of Hamas' internal security service broke into Abu Saif's house at dawn and seized his laptop and cell phone and took him with them, his family said.

In a statement calling for his release, Israeli's Foreign Press Association warned of the consequences of acting against foreign journalists based in Gaza.

"Events such as this seriously affect the international media's ability to cover Gaza," the association warned. "Without basic guarantees of safety, such coverage is likely to decrease, to the detriment of Gaza's people and the free practice of journalism."

The de-facto Hamas administration in the Gaza Strip on Monday banned three major West Bank-based Palestinian daily newspapers.

The Hamas-run Interior Ministry said it had blocked their distribution because of what it described as their unfair coverage of a bombing attack on a Hamas car on Friday.