Hundreds of Gazans flocked into Sinai after breaching the border on Sunday, prompting Egyptian policemen to shoot into the air in a desperate attempt to stop them. An Egyptian border guard was killed as security forces and Palestinian gunmen exchanged fire. The Egyptians, meanwhile, accused Hamas and the Muslim Brotherhood of inciting against the regime of President Hosni Mubarak. Hussam Zaki, spokesman for the Egyptian Foreign Ministry, said the anti-Egyptian demonstrations in some Arab capitals were directed against the "wrong address." Under pressure from the Arab street, Mubarak on Sunday decided to reopen the Rafah border crossing to allow the delivery of food and medicine to the Gaza Strip. Eyewitnesses said that many of the fleeing Palestinians hurled abuse at the Egyptian border policemen and accused them of collaboration with Israel. The Palestinians also shouted slogans condemning Mubarak and Palestinian Authority President Mahmoud Abbas, the eyewitnesses said. They added that several Palestinians were wounded by Egyptian gunfire and taken to hospital in Egypt. The Palestinian started pouring into Sinai shortly after IAF planes bombed four smuggling tunnels under the border between the Gaza Strip and Egypt. Fearing that a massive IDF operation in the Gaza Strip would force thousands of Palestinians to infiltrate the border, the Egyptian authorities beefed up security measures near the Rafah border crossing 24 hours before the attack on the tunnels. Meanwhile, Cairo and the PA strongly denied allegations by Hamas that they had given Israel a green light to attack the Strip and held the Islamist movement responsible for the "massacres" in Gaza by refusing to extend the unofficial cease-fire with Israel. Abbas, who held talks in Cairo on Sunday with Mubarak and Foreign Minister Ahmed Aboul Gheit, said Hamas was responsible for the violence because it had ignored his request to renew the cease-fire, which expired 10 days ago. Abbas said he and his aides had contacted Hamas figures numerous times, directly and indirectly, to urge them to renew the cease-fire, but to no avail. "We begged them not to end the cease-fire so as not to give Israel an excuse to launch its aggression," Abbas told reporters. "We condemn this aggression and we want dialogue with Hamas." Abbas added that the PA, and not Hamas, was responsible for the Palestinians. His remark was seen as an indication of his desire to regain control over the Gaza Strip after Hamas is ousted from power. Gheit also lashed out at Hamas and accused it of preventing wounded Palestinians from crossing into Egypt for medical treatment. Cairo, he said, offered to take scores of wounded Palestinians, but Hamas banned them from travelling through the Rafah border crossing. Hamas spokesman Fawzi Barhoum denied the allegation, claiming that many of the wounded rejected an Egyptian offer to receive medical treatment in Cairo in protest against Cairo's "support" for the IDF operation. He accused the Egyptians of taking part in the "siege" on the Gaza Strip by refusing to reopen the Rafah crossing. A plane carrying some 50 Egyptian physicians arrived in el-Arish on Sunday as part of Cairo's efforts to help the Palestinians in the Gaza Strip. The physicians are hoping to enter the Strip to treat hundreds of wounded Palestinians. Ahmed Abdel Rahman, a senior aide to Abbas, held Hamas responsible for the death of "dozens" of Fatah members who were being held in Hamas-controlled prisons. He claimed that Hamas deliberately kept the detainees in prison so that they would be killed by the Israeli air strikes.