KABUL, Afghanistan -- Afghans offered solemn prayers and hopeful songs from children Sunday as they kicked off a landmark constitutional convention -- a key step in the two-year drive to stabilize the battle-scarred country. Security was tight in the capital, with sharpshooters on rooftops and hundreds of soldiers lining the streets, after warnings from the U.S. military that Taliban militants might try to attack the convention. Some 500 delegates -- from village mullahs to Western-educated exiles -- gathered under a huge tent here to hammer out a new constitution in a traditional loya jirga, or grand council.
They are expected to spar over the role of Afghan women, Islam's place in politics and the sharing of power in a nation accustomed to fighting over it.
Their former king urged them to overcome the deep ethnic divides left by more than two decades of conflict.
"The people are relying on you and you should not forget them," the 88-year-old former monarch, Mohammad Zaher Shah, told the assembly. "I hope you will try your best to maintain peace, stability and the unity of the Afghan people."
"We are set to determine the future of the nation and of coming generations," President Hamid Karzai said in a speech. "This constitution will guarantee the rights of all Afghan people ... and put an end to anarchy."
But arguments at the start of the convention over Karzai's authority exposed the difficulty of securing agreement on the country's first post-Taliban charter.
The gathering comes two years after a U.S.-led offensive drove the Taliban from power and is supposed to pave the way for landmark presidential elections slated for June.
Many of the men wore fine silk robes, some with western suit jackets slung over them. Yellow, burgundy and cream colored turbans jutted out from the crowd. Female representatives arrived in all-enshrouding burqas, but took them off once inside.
Delegates, diplomats and reporters were patted down for weapons and explosives as they entered the tent.
Officials hope the constitution will produce a government able to repel the resurgent Islamic militia and its allies -- an effort that could get a boost from Sunday's capture of former Iraqi leader Saddam Hussein.
Omar Samad, a spokesman for the Afghan Foreign Ministry, said Saddam's arrest by U.S. forces "is a warning to all the other outlaws who are at large" like bin Laden, Taliban chief Mullah Omar and renegade Afghan warlord Gulbuddin Hekmatyar.
For U.S. officials pushing the process, Afghans' experience could provide lessons for Iraq, where American administrators have faced an even tougher task in drawing up a constitution.
"To the members of the loya jirga, I say you are making history," said U.S. Ambassador Zalmay Khalilzad in an open letter. "The people you represent are watching you with great anticipation. And the world is watching as well."
Officials hope the loya jirga, meeting at a Kabul college campus, will take about 10 days to finalize a 160-article draft drawn up by a constitutional commission.
Delegates are divided under pressure from U.S.-backed Karzai for a strong chief executive, with opponents pushing for a prime minister who would share power. Karzai this week said he would not stand in next year's elections if a strong prime minister's post is created.
Karzai scored an early victory Sunday evening when an Islamic moderate viewed as a close ally was elected chairman of the council. Sibghatullah Mujaddedi, an aristocratic former president, secured 252 votes.
Some fear the power struggle will overshadow issues like the rights of women, or that the president would bargain away too much to religious hard-liners in return for their support for a presidential system.
The fault lines were quickly evident Sunday, as speakers aligned with the Northern Alliance, the anti-Taliban coalition dominated by ethnic Tajiks from the north, challenged Karzai's right to appoint 50 of the delegates.
"The order issued by the president is completely illegal," said Hafiz Mansour, the publisher of a Northern Alliance-affiliated newspaper who won 154 votes in the runoff for the chairmanship.
But Pashtuns -- the country's largest ethnic group -- rallied around Karzai, saying he was the only figure capable of uniting the country and taming its feuding warlords.
"If the people support Karzai, the commanders can do nothing," said Saif Ul Malouk, from Washir in southern Helmand province. "They will have to join the people."