Israel closed its cargo crossings with Gaza Tuesday because of Palestinian rocket fire at Israel, just a day after allowing vital humanitarian supplies in. The IDF said Palestinian gunmen fired a rocket at Israel on Monday and another on Tuesday, and the crossings were closed on Tuesday as a result. The rocket fire and the border blockade are evidence that a five-month cease-fire that stopped rocket barrages from Gaza and Israeli retaliation may be close to breaking down. Even though the crossings were opened to allow 42 truckloads of supplies in on Monday, foreign correspondents were still not allowed in to Gaza. The ban on reporters has been in effect for more than two weeks. In Washington, visiting Prime Minister Ehud Olmert was asked about the ban. He replied, "The reason the passages are closed is completely related to security matters ... we didn't want to take responsibility for the safety of journalists passing through." Up to now, foreign correspondents have been allowed to enter Gaza with few restrictions, even when heavy fighting is going on. Last week Defense Ministry spokesman Shlomo Dror said Israel was displeased with new coverage of Gaza, charging that it overplayed Palestinian suffering without adequate explanation of Israel's reasons for closing the border. On Tuesday Israel's Supreme Court ordered the government to respond within 15 days to an appeal by the Tel Aviv-based Foreign Press Association against the ban. The FPA, which represents foreign correspondents working in Israel and the Palestinian areas, said it would consider appealing for a quicker hearing. Last week heads of leading world news organizations sent a stern letter to Olmert demanding that he lift the ban on reporters entering Gaza and honor Israel's long-standing commitment to press freedom. Talking to reporters in Washington on Tuesday, Olmert said he had not read the letter. "There are security situations in which certain restrictions are set for a short period and it doesn't mean the Israeli government is trying to hide something in the Gaza Strip," he said. "We are not doing anything in the Gaza Strip that we have to hide." Olmert also denied that there is a humanitarian crisis in Gaza, though Palestinians complain of severe shortages.