Thousands of Palestinians took to the streets in the West Bank and Gaza Strip Tuesday to express their opposition to the US-sponsored peace conference in Annapolis, Maryland, as Palestinian Authority officials expressed cautious optimism over the results of the meeting. "I feel that the real battle has begun now," said Nabil Amr, a top advisor to PA President Mahmoud Abbas. "The hard talks are still awaiting us. We must look seriously at the next phase." Amr said he was encouraged by the growing involvement of the Americans and Europeans in the peace process. He also said that any agreement reached with Israel would be presented to the Palestinians through a national referendum. "The Palestinians will be asked to approve any agreement," he added. "Palestinians living outside the West Bank and Gaza Strip will also have the right to vote. If our people reject the agreement, we will cancel it. If they approve it, we will move forward with it." A senior PA official in Ramallah said he did not rule out the possibility that the Palestinians and Israelis would be able to reach a comprehensive agreement by the end of 2008 - in line with US President George W. Bush's vision. But, he warned, in order for that to happen, the US and the international community must be involved in the Israeli-Palestinian negotiations "from day one to the end. Without pressure from outside on Israel, there can be no progress." Fahmi al-Za'arir, a Fatah spokesman in the West Bank, praised the PA negotiating team in Annapolis for reiterating all the Palestinian demands. He stressed that his faction remained opposed to the idea of normalization between Israel and the Arab countries before a final settlement is reached on the Palestinian issue. He too expressed confidence that the two sides would be able to reach a deal before the end of next year "provided that Israel displayed goodwill and a genuine desire to end the occupation." Despite the tone of optimism, some PA officials said they were skeptical that the two parties would be able to resolve all the major issues in such a short period of time. One official described Bush's vision as "unrealistic," while another said he did not believe that Prime Minister Ehud Olmert would remain in power for too long. Hamas described the Annapolis gathering as a "second nakba [catastrophe]" for the Palestinians and Bush's talk about a Palestinian state as an illusion. "Through his inflammatory speech, Bush is trying to instigate civil war among the Palestinians," said Hamas legislator Salah Bardaweel. "Bush talked today as a Crusader and Zionist." Bardaweel also launched a scathing attack on Abbas, saying he did not have a mandate to negotiate with Israel. "Hamas represents the majority of the Palestinians," he added. "Abbas has no right to make any concessions." Hamas leader Mahmoud Zahar told demonstrators in Gaza City that any Palestinian who gives up one inch of the land of Palestine would be tried as a traitor. "Palestine, from the sea to the river, is all Muslim-owned," he said. "The right of return to Haifa, Jaffa and Jerusalem is non-negotiable." Tuesday's protests in the West Bank, the largest since Hamas's violent takeover of the Gaza Strip last June, came despite a ban imposed by the PA leadership on anti-Annapolis demonstrations. One Palestinian, Hisham al-Baradi, 37, was killed and dozens injured during clashes between the demonstrators and security forces loyal to Mahmoud Abbas. Several journalists covering the protests were beaten by PA policemen. The PA security commander of Hebron, Gen. Sameeh al-Saifi, was injured in the face by a stone. The demonstrations in Ramallah, Hebron, Nablus and Tulkarm were organized by Hamas and another radical Islamic group called Hizb al-Tahrir.