Hundreds of thousands of Syrians swarmed downtown Damascus Thursday in a government-orchestrated rally to protest Israel's military offensive against the Gaza Strip. It was the biggest protest ever in the Syrian capital since Israel launched an air and ground offensive on the Hamas-ruled Gaza Strip Dec. 27. The protest was called by Syria's labor unions. Syria's official news agency SANA and the state-run Syrian Television estimated the number of protesters in downtown Damascus at roughly one million. But independent estimates put it at hundreds of thousands. Demonstrators in downtown Damascus carried pictures of Syria's president and the leader of Lebanon's militant Hezbollah, both of whom support Hamas. The crowd, waving Syrian and Palestinian flags, also yelled protests against Egyptian President Hosni Mubarak for refusing to open the Rafah border crossing with Gaza. Many in the Arab world have criticized Egypt for this, perceiving it as abetting Israel. "Oh Mubarak, listen, listen, the Arab people will not kneel down," the protesters shouted. Before the huge demonstration dispersed, an estimated few hundred of the protesters, marched to the Egyptian Embassy. The protesters, standing about 110 yards (100 meters) from the embassy, were prevented by Syrian riot police, carrying batons and protective shields, from reaching the building. The protesters in downtown Damascus also trampled on an Israeli flag before burning it. Some of the banners they carried read, "The Gazans' blood will not be shed in vain," and "Your blood is pure, Oh Gaza's people ... and the blood of Arab leaders stinks." Mayadah Nashawati, a 50-year-old housewife, who was at the protest said: "Israel is committing a genocide at a time when the entire world is regretfully watching." She said the Rafah crossing, which connects the Gaza Strip's 1.4 million residents with Egypt, must reopen to "salvage the Gazans from the holocaust." Ahmed al-Hamid, a 17-year-old student, also urged Mubarak to open the Rafah crossing. "The Arabs must break their silence on the injustice that has befallen the Palestinian people," he said. Israel has said that it started its campaign in order to stop Hamas rocket fire. More than 700 Palestinians have been killed since the offensive began. Meanwhile, an Egyptian foreign ministry official lashed out Thursday at Hassan Nasrallah, the leader of the militant group Hezbollah, for remarks Nasrallah made against Egypt in his latest speech. The official, who did not want to be identified due to the sensitivity of the issue, said so far the militant leader has given "nothing to Gaza but some ringing speeches."