Egyptian authorities are investigating claims that many Gazans bought land in Sinai in the past few weeks. Leaders of several Beduin tribes living in Sinai have sent a message to Egyptian President Hosni Mubarak in which they strongly denied that their families sold land to Palestinians who poured into Egypt after the border was breached on January 23. Egyptian law prohibits foreigners from purchasing land in Sinai. The investigation comes amid growing tension between Egypt and Hamas over the tearing down of the security fence along the border with the Gaza Strip. Sources close to Hamas said Egyptian authorities have decided to suspend contacts with the Hamas leadership in protest of the breaching of the border. The sources told The Jerusalem Post that Cairo had also declared Damascus-based Hamas leader Khaled Mashaal persona non grata. In addition, several Hamas leaders from the Gaza Strip have been told they would not be allowed to enter Egypt. They include Hamas Prime Minister Ismail Haniyeh, Mahmoud Zahar and Said Siam. Egyptian Foreign Minister Ahmed Aboul Gheit issued a strong warning to Hamas on Thursday. "Anyone who violates Egypt's borders will get his legs broken," Aboul Gheit was quoted as saying. He added that Egypt only allowed the Palestinians to cross the border after Hamas blew up the wall because of the humanitarian crisis resulting from Israel's blockade of the Gaza Strip. He blamed Israel for the hardship that Gaza was experiencing, and for "responding to the Palestinian missiles with collective punishment." Aboul Gheit also criticized Hamas for firing rockets at Israel, accusing the movement of "laughable caricature" resulting in self-inflicted wounds. "After Hamas's takeover of Gaza, it has decided to clash with Israel, though this clash seems to be a laughable caricature, because clashing with an opponent in battle is supposed to mean damaging them," Aboul Gheit said. "You do not go into battle just to damage yourself." He said Hamas's rockets either fell in Gaza and wounded Palestinians or gave the Israelis a pretext to attack them. In their message, the Beduin leaders said they opposed selling their land to Palestinians or to any other "foreigners." Mubarak dispatched the governor of northern Sinai, Ahmed Abdel Hamid, to warn the Beduin in Sinai against selling land to Palestinians. Palestinian sources claimed earlier that dozens of families from the Gaza Strip who crossed into Sinai have purchased thousands of dunams of land from Beduin tribes there. "The Egyptian fear that Palestinian families are planning to settle in Sinai," the sources added. The semi-official Al-Ahram newspaper in Cairo reported on Thursday that Egyptian security forces have rounded up some 650 Palestinians who were staying in el-Arish. It said the Egyptians were planning to deport them to the Gaza Strip in the coming days. According to the report, Egyptian authorities have also seized 22 vehicles with Palestinian registration plates. Hamas officials, meanwhile, confirmed that many Arab men had visited the Gaza Strip to volunteer to fight against Israel. But the officials said that most of the men were asked to leave because Hamas already had enough volunteers. Defense officials said there were indications that large numbers of foreigners had entered the Gaza Strip following the collapse of the border wall between Gaza and Egypt. The officials said that while there was information backing up the Hamas claims, the defense establishment had yet to notice signs of the formation of a new terrorist group made up of the foreigners. The entry of the foreigners into Gaza was not surprising, the officials said, adding that Muslim extremists have previously infiltrated other countries, such as Iraq, to participate in attacks. Coalition forces have claimed for years that Syria was turning a blind eye to thousands of foreign terrorists who used its border to infiltrate Iraq and participate in the fight against US troops. The Shin Bet (Israel Security Agency) has also warned of a dramatic increase in the number of anti-tank missiles, anti-aircraft shoulder-to-air missiles and sophisticated long-range rockets that were smuggled into Gaza during the 12 days that the border with Egypt was open.