BAGHDAD - The secular challenger who stunned Iraq with his razor-thin parliamentary election win turned his attention to negotiations over a future government Saturday even as supporters of the prime minister vowed to fight the results.

Ayad Allawi's two-seat win was hailed as a startling comeback for a politician who just four years ago was shunned as a U.S.-backed puppet, but the closeness of the race meant his road to regaining the premiership was anything but guaranteed.

Prime Minister Nouri al-Maliki's bloc has demanded a recount, claiming fraud. The Shiite leader, who angrily denounced the results after their Friday release, did not appear in public on Saturday, but his supporters promised a fight to keep him in his post.

"There are two options in front of us. The first, to continue the challenge in a legal and constitutional way and the second is to continue demanding the manual recount," adviser Sami al-Askari said.

A spokesman for the Accountability and Justice Commission, responsible for vetting candidates for ties to Saddam Hussein's Baathist party, also raised the prospect that some candidates may yet be disqualified.

The maneuvering followed a bitter campaign and signaled a protracted battle to form a new government that will lead the country as the U.S. speeds up the withdrawal of its forces.

In a worrying sign of the sectarian tensions the elections have stirred up, a Sunni leader in a Baghdad neighborhood who on Friday night celebrated Allawi's win by passing out candy to well-wishers was killed by a sniper Saturday morning, police and hospital officials said.

Regardless of the final outcome, the results of the parliamentary vote were a turning point and served as a rejection of the domination of Shiite religious parties who are closely aligned with Iran and rose to power after the U.S.-led invasion ousted Saddam's Sunni-dominated regime in 2003.

The vote also served as a referendum against the sectarian politics that had pushed the country to the brink of civil war after tensions between Shiites and Sunni Arabs were unleashed.

Allawi's Iraqiya coalition won 91 seats to 89 for al-Maliki's bloc, riding a wave of support from Sunnis frustrated with the Shiite-dominated government, which they say has incited sectarian tensions and is too closely aligned with neighboring Iran.

But both groups fell far short of the 163 seat majority needed to form a government alone, leaving a Shiite religious coalition including anti-American Muqtada al-Sadr known as the Iraqi National Coalition and U.S.-allied Kurds as likely kingmakers.

Political blocs have three days to appeal the results, which will not be final until certified by the Supreme Court.

Further complicating the situation, al-Maliki won a ruling from the Supreme Court this week that left the door open for another bloc formed through political negotiations after the election to win the right to choose the new prime minister. That could boost his chances of keeping his job if he can win enough allies in the coming weeks or months.

Al-Maliki "will not go down without a fight. We basically have a prime minister refusing to accept the election results and this talks volumes about the fragility of the rule of law in Iraq," said Toby Dodge, an analyst with the International Institute for Strategic Studies in London.

A senior U.S. Embassy official, Gary Grappo, acknowledged that the prime minister's coalition would take "advantage of all the means at their disposal to try and eke out a victory."