(Adds details, Palestinians say blast caused by rocket) GAZA, Nov 28 (Reuters) - A rocket blew up as it was being launched by Palestinian militants on Tuesday, causing a loud explosion in northern Gaza but causing no casualties or damage, Palestinian security officials said. The rocket was the latest of more than a dozen fired by militants at Israel in violation of a truce that took effect on Sunday, after five months of fighting since the June capture of an Israeli soldier in a cross-border raid. The blast was heard near the Palestinian intelligence headquarters in Gaza City, a security source said, sparking fears it was an Israeli attack, but it emerged that was not the case. There were no immediate claims of responsibility for the rocket. Several hours earlier an armed wing of Palestinian President Mahmoud Abbas's Fatah movement claimed responsibility for firing a rocket from northern Gaza at the Israeli town of Sderot, which caused no injuries. Israeli Prime Minister Ehud Olmert said earlier he was disappointed by Palestinian rocket firings despite the ceasefire, but Israel would exercise restraint for now. Palestinians have accused Israel of violating the spirit of the truce by continuing to carry out raids on militant hideouts in the occupied West Bank, killing one gunman on Monday in an area not covered by the truce agreement. U.S. President George W. Bush was due in the region on Wednesday for talks in Jordan with Iraqi and other regional leaders.
