Iraq's main Sunni Arab coalition has challenged partial vote results showing a strong lead for a Shi'ite coalition in last week's parliamentary elections.

Leaders for the Iraqi Consensus Front said the preliminary totals did not match those recorded by party monitors in Baghdad province, and warned they may call for a re-vote.

Initial results show the Sunni coalition received 19 percent of the vote, and the Shi'ite-led United Iraqi Alliance took 59 percent in Baghdad. Final results are expected early next month.

Meanwhile, U.S. Ambassador Zalmay Khalilzad expressed concern that results showed votes in other parts of Iraq were mostly divided along religious and ethnic lines. He said Iraq's future relies on cross-ethnic cooperation.

In Washington, President Bush called Iraqi President Jalal Talabani and Prime Minister Ibrahim al-Jaafari Tuesday to congratulate them on the election.

Some information for this report provided by AFP and Reuters.