Jerusalem - German public broadcaster ARD on Wednesday closed its office in the Gaza Strip in protest against the detention of one of its cameramen by Hamas five days earlier, while Israel's Foreign Press Association again called for his release.

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

The crackdown in the Hamas-controlled salient followed a series of bombings in and around Gaza City on Friday in which six people were killed and for which Hamas is blaming Fatah.

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.

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

"Everyone who works with him know and say the allegations against him are baseless."

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

Israeli's Foreign Press Association in a statement calling for his release, 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. 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 association warned.

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

The Hamas-run Interior Ministry said it blocked their distribution in the Gaza Strip because of what it described as their unfair coverage of a bombing attack on a Hamas car on Friday. (dpa)