George W Bush is on the verge of victory and re-election to a second term as the American president.

However, questions over provisional ballots - ballots that were cast pending authentication - in Ohio threatened to delay a final verdict for as long as two weeks.

According to news agency Reuters , two television networks projected Bush would win Ohio, but three others did not.

The campaign aides of his opponent, Democratic Senator John Kerry, said they would not concede the state until all votes, including an unknown number of provisional ballots, were counted.

With 270 electoral votes needed to win the White House, Bush has captured 28 states with 254 while Kerry won 20 states and 252 votes, with Ohio (20 electoral votes), Iowa (7) and New Mexico (5) still to be decided .

However, Bush is leading by a small margin on all the three still-to-be-decided states.

The incumbent also bagged 57,684,133 (51%) votes while the Democratic challenger pull in 54,087,699 (48%) votes.

Reuters said Bush captured Florida, the biggest of the toss-up battleground states, and secured wins across the country to move to the edge of victory. Kerry won Pennsylvania's 21 electoral votes but New Hampshire was the only state won by Bush in the bitter 2000 election that he had captured.

Heavy turnout

Heavy voter turnout was reported nationwide and few major glitches were recorded. Dire predictions of voter challenges and election chaos mostly did not come true in an election where turnout was expected to sail well past the 105 million Americans who voted in 2000.

Kerry's campaign manager Mary Beth Cahill was quoted as saying that "the vote count in Ohio has not been completed. There are more than 250,000 remaining votes to be counted. We believe when they are, John Kerry will win Ohio."

An unknown number of those votes were provisional ballots issued to voters when their registration was challenged.

Ohio Secretary of State Ken Blackwell said those votes would not be counted for 11 days.

"If the number of votes that make up the difference between the two candidates is fewer than the number of provisional ballots, then I would say everybody should just take a deep breath and relax because we're not going to start counting those ballots until the 11th day after the election," he said.

He said there could have been as many as 175,000 provisional ballots cast, though the figure was speculative and will not be known for sure until all counties have reported.

With more than 96 percent of the state's precincts counted, Bush was leading Kerry by 166,072 votes, according to totals provided by Blackwell's office.

Bush's win in Florida, where his brother Jeb is governor, gave him a giant boost in his bid for re-election and added 27 electoral votes to his column.

Voters also were deciding which party holds power in Congress and will vote on governorships in 11 states, with Bush's Republicans retaining control of the Senate and House of Representatives.

Republicans won Senate seats in North Carolina, Georgia, South Carolina and Louisiana, and Democrats picked up seats in Illinois and Colorado.

Disputes in key states

According to Reuters , a few disputes broke out in key swing states as officials began to count ballots. A Philadelphia judge blocked the counting of up to 12,000 absentee ballots in the city until he holds a hearing on Wednesday after a complaint brought by the Republican Party.

Thousands of people were still in line waiting to vote more than two hours after the polls closed in Ohio, and officials said they would be allowed to stay in line as long as they were there at closing time.

Bush won one-time battlegrounds like West Virginia, Arizona and Missouri and Kerry took New Jersey while both candidates scored a series of wins in states where they were prohibitive favourites.

Bush and Kerry cast votes in their home states of Texas and Massachusetts, respectively, earlier in the day then settled in for a long night of watching and waiting. Bush, who watched the results in the White House with his family, including his father, former president George Bush, said he was confident of victory.

"We're very upbeat, thank you. I believe I will win," he told reporters.

Kerry, watching the results in his hometown of Boston, did not make an appearance before reporters but sent out aides to predict a win.