VIDEO - The Israel Air Force on Saturday night attacked the office of Palestinian Prime Minister Ismail Haniyeh in Gaza, causing a fire in the building. According to Palestinian eyewitnesses, two missiles hit the northern part of the building containing the office, which was empty due to the late hour. Sources in the city's hospital said that one person was injured in the attack. The Israel Defense Forces confirmed the Saturday night attack, explaining that it was a clear message conveyed to the Palestinian prime minister. In a statement issued after the incident, the army said: "Hamas is a terror organization which initiates and carries out terror activities against Israel, including in recent days. The IDF views the Hamas-led government as responsible for the latest terror attack and for the fate of abducted soldier Corporal Gilad Shalit." The IDF said that it intentionally chose to attack the target late at night in a bid not to risk human life, but still convey a message to Hamas leaders. Haniyeh arrived quickly to survey the damage done to his Gaza offices and to condemn the attack. "This is the policy of the jungle and arrogance," Haniyeh told Reuters. "Nothing will affect our spirit and nothing will affect our steadfastness." After the Israeli air strike on his office, Haniyeh met with Palestinian President Mahmoud Abbas for an hour to discuss the Israeli attacks and efforts to keep the government functioning despite the arrests, the prime minister's office said. In a statement, Haniyeh called for foreign intervention to stop the Israeli offensive. "The international community must shoulder its responsibility," he said. A short while after bombing Haniyeh's office, the Air Force attacked two more targets in the northern Gaza Strip. IDF officials said that the targets were Hamas buildings in which Palestinian gunmen planning to carry out terror attacks against Israel were hiding. "The security forces will operate against the terror organizations and their activists, regardless of their ranks or organizational affiliation, in order to enable the unconditional return of Shalit and the halting of terror activities against Israel," the army's statement said. Haniyeh arrives at his blasted office (Photo: AFP) Palestinian sources reported that one of the targets attacked was the al-Akram school, which was build with funds donated by Sheikh Ahmad Yassin. The second target was the headquarters of Hamas' security forces. One person was killed in the last attack. Over the weekend, the Air Force struck a large number of targets in the Strip, including the Palestinian Interior Ministry, offices belonging to the al-Aqsa Martyrs' Brigades, and Hamas training camps. In addition, the army blasted the office of senior Hamas leader Said Siam in the northern Gaza Strip, which had served, according to the army, as a meeting place for planning and directing terror activities. On Sunday morning, Palestinians fired an anti-tank missile at IDF soldiers operating at the Dahaniya Airport, near Rafah. Over the weekend, the IDF fired more than 1,000 shells at the Strip. Karni crossing to open for delivery of humanitarian aid On Saturday evening, Defense Minister Amir Peretz instructed the army to open the Karni crossing for four days, in order to enter 150 trucks a day into the Gaza Strip with humanitarian equipment from the United Nations and other international organizations. A second terminal is expected to open for the entry of petrol and diesel fuel in the northern Strip. Peretz instructed Yossi Mishlav, the coordinator of the government's operations in the territories, to closely examine the humanitarian issue. Israel does not want to reach a situation in which the world will view difficult pictures of hungry civilians or civilians in need of medications in the Gaza Strip. Military officials and state officials know that continuing the siege on the Strip, regardless of whether a military operation is launched, will only add to the complexity of the situation. Collecting fuel (Photo: AFP) The United Nations agencies expressed their concern over the weekend in light of the deteriorating humanitarian situation in Gaza, with heavily damaged roads, water pipes and relay stations. An estimated 130 Gaza wells require electricity to pump water, and while some have backup pumps that run on diesel fuel, Israel has allowed no fuel to flow into Gaza for four days, leaving it dependent on emergency supplies expected to last another three days. The UN chief aid warned on Thursday that Gaza is three days away from a deadly humanitarian crisis unless Israel promptly restores fuel and electricity to the densely populated area after its offensive to free an abducted soldier, the UN aid chief warned on Thursday. "They are heading for the abyss unless they get electricity and fuel restored," said Emergency Relief Coordinator Jan Egeland, who also urged the Palestinians to free the soldier and clamp down on militants firing rockets into Israel. I am confident that neither of the two want to see a massive increase in mortality in the Gaza," where children make up about half of the area's 1.4 million people, Egeland told a small group of reporters. At the heart of the crisis, he said, was Israel's bombing of Gaza's sole power plant, which supplies about 40 percent of the area's electricity. The remaining power comes from Israel. Another difficult problem has been created at the Rafah crossing. A senior Egyptian official reported that more than 4,000 Palestinians have been stuck in the Egyptian Rafah and in al-Arish, waiting for an opportunity to return to the Strip. According to the Egyptian officer, many of the Palestinians waiting at the border arrived from Gulf States, where they work throughout the year. They usually return home for a summer holiday with their families. Hundreds of Palestinians have been stuck at the Rafah crossing for a week, after the Egyptians stamped their passports, but are unable to cross to the Palestinian side of the border. A big tent has been built outside the terminal, in order to provide a shelter for women and children due to the great heat. Egypt is providing food for the Palestinians, who have become refugee against their own will. News agencies contributed to the report