WASHINGTON --Bahrain ordered its military off the streets Saturday, responding to a key demand by the opposition for starting a dialogue in the political crisis a day after security forces opened fire on anti-government protesters. But a prominent opposition leader said the withdrawal of army tanks and armored personnel carriers from the capital of Manama is not enough to open talks with rulers in the crisis-wracked Gulf nation. Ibrahim Sharif, head of the Waad Society, demanded guarantees that protesters can stage rallies without fear of being attacked. Waad is an umbrella group of protest factions. Jubilant Bahrainis honked car horns, waved flags and flashed v-for-victory signs as the armored vehicles began moving away from Pearl Square, the symbolic center of their uprising against the Sunni monarchy in the predominantly Shiite nation. An Associated Press photographer saw a contingent of riot police who replaced the military forces fire tear gas at people celebrating the military withdrawal from the square and detain at least 10 people. The riot police then left their positions, got into vehicles and drove away, allowing thousands of cheering protesters carrying Bahraini flags, flowers and signs that said "Peaceful, peaceful" to march to the square. "We are victorious," the protesters chanted. On Friday, army units opened fire on marchers streaming toward the square, . More than 50 people were injured in the second consecutive day of clashes. Thousands of protesters took over the square earlier in the week, setting up a camp with tents and placards, but they were driven out by riot police in a deadly assault Thursday that killed five people and injured more than 200. The government clamped down on Manama by sending the tanks and other armored vehicles into the streets around the square, putting up barbed wire and establishing checkpoints to deter gatherings. According to a government statement, the withdrawal order came from Crown Prince Salman bin Hamad Al Khalifa, deputy supreme commander of the armed forces and the member of the royal family who has been designated to open a dialogue with protest leaders. The statement said he had ordered "the withdrawal of all military from the streets of Bahrain with immediate effect." "The Bahrain police force will continue to oversee law and order," the statement said. It was not immediately clear if the tanks and other armored vehicles were headed all the way back to military bases. The crown prince appealed for calm and political dialogue in a brief address on state TV. "The sooner we return to calm, the sooner we can reach our goals," Salman said. "Citizens of Bahrain, let's work together with all political blocks to help return the security situation to normal so we can announce a day of mourning for those we've lost." U.S. President Barack Obama discussed the situation with King Hamad bin Isa Al Khalifa, asking him to hold those responsible for the violence accountable. He said in a statement that Bahrain must respect the "universal rights" of its people and embrace "meaningful reform." Protesters who tried to march to the square Friday described a chaotic scene of tear gas clouds, bullets coming from many directions and people slipping in pools of blood as they sought cover. Some claimed the gunfire came from either helicopters or sniper nests. The clash came hours after funeral mourners and worshippers at Friday prayers called for the toppling of the Western-allied monarchy in the tiny island nation that is home to the U.S. Navy's 5th Fleet, the centerpiece of the Pentagon's efforts to confront Iranian military influence. Some members of Bahrain's Sunni ruling system worry that Shiite powerhouse Iran could use Bahrain's majority Shiites as a further foothold in the region. The cries against the king and his inner circle -- at a main Shiite mosque and at burials for those killed when security forces attacked a protest camp in Pearl Square -- reflect a sharp escalation of the political uprising, which began with calls to weaken the Sunni monarchy's power and address claims of discrimination against the Shiite majority. The mood, however, has turned toward defiance of the entire ruling system after the crackdown, which put the nation under emergency-style footing with military forces in key areas and checkpoints on main roads.