Jamaica's opposition Labour Party (JLP) has won the general election, ending an 18-year reign by the People's National Party (PNP), preliminary results show.
JLP leader Bruce Golding called for an orderly transition of power
The JLP, led by Bruce Golding, has taken 31 out of the 60 seats in parliament, election officials said.
But Portia Simpson Miller, Jamaica's first woman Prime Minister, has not acknowledged defeat and indicated that the PNP would challenge the result.
Crime, poverty and high unemployment were the main issues in the campaign.
Jubilant JLP supporters took to the streets of the capital, Kingston, to celebrate their apparent win.
Hundreds gathered at the party's headquarters cheering wildly and chanting "Bruce, Bruce" as Mr Golding took to the stage to the strains of Bob Marley.
Portia Simpson Miller: Election too close to call
The JLP leader made a cautious speech, avoiding a claim of outright victory.
"However perplexing some may find the results, the fact is that the people have spoken and we of the Jamaica Labour Party, we accept and respect the decision," said Mr Golding.
"At the moment, the Jamaica Labour Party commands a majority of seats in parliament," he said.
He called for a transition of power in an orderly and peaceful manner.
But Mrs Simpson Miller, who has been in power for 18 months, said a number of races were so close that the results could change after a recount.
"The election is too close to call," she told supporters at the PNP's headquarters.
"We are conceding no victory to the Jamaica Labour Party," she said, adding that there had been reports of irregularities.
The narrowness of the election result and the PNP's refusal to concede presents the Jamaican electoral authorities with a big challenge, says the BBC's Orin Gordon in Kingston.
JLP supporters are already celebrating
A recount needs to proceed swiftly to end all doubts about the result, he says.
The director of elections, Danville Walker, told Reuters news agency that a recount would begin on Tuesday and that the process would take two to three days.
About three constituencies were "closer than razor thin", he said.
The voting itself was largely peaceful, but in the St Andrews area of Kingston shots were fired at a polling station from a car.
The two main parties do not differ significantly in ideology. Analysts say voters may have been looking for a change to tackle Jamaica's deep-seated poverty, 9% unemployment and a murder rate that is among the highest in the world.
The election had been scheduled for 27 August but was postponed for a week after Hurricane Dean swept through the island, causing widespread damage.
Now that the people of Jamaica changed the course of the PNP, Portia must get out of Bruce's house ASAP.
Wayne Daley, Kingston, Jamaica
Jamaica is improving dramatically. The governing party, PNP is doing their utmost for Jamaica. Jamaica has improved and it is still improving as we speak. This election is very important because we will find out if all people in Jamaica want to continue changing in the right direction or want a difference. For sure Portia Simpson-Miller, PNP President and current PM will win.
Theo Monteith, Mandeville, Jamaica
Yes I voted. This is a well deserved victory not only for the JLP but for the people of Jamaica as a whole. Jamaica needed this change in government as we move forward. The high crime rate, poverty, poor living conditions and the dim future facing the youths are just some factors which I think will be handled better by this new government to be sworn in.
Damian Lewis, Kingston, Jamaica
I strongly believe that no matter what party is in power, the violence and poverty will not be changed in Jamaica. The citizens of Jamaica need to realise that killing each other is useless. Why can't voters go out and vote without worrying for our lives? Jamaicans live in fear at these times.
Liatany, Kingston, Jamaica
To be completely honest, I fail to understand the major differences (if any) between the PNP and the JLP. Both institutions seem to be preaching similar ideologies, and the deciding factor in this election, as in every election, will be based not on the political manifestos, but rather on the candidates' perceived personal integrity (and of course, outlandish promises).
Edwin Clarkson, Montego Bay, Jamaica
Most Jamaicans were excited when Portia Simpson became Jamaica's first female prime minister. They had high hopes for her. However after the euphoria her popularity gradually declined. She cannot believe she was voted out and is protesting the results. Bruce Golding on the other hand was not gloating over his win but showed concern for all Jamaicans.
Janice Rennalls, Kingston, Jamaica
If Mr Golding did win this election, then I hope he will do a good job of leading Jamaican out of these difficult times, with high employment and crime. I am a PNP supporter and would have liked Miss Simpson to have a four year term to see what she could do for the country. She was our first women prime minister so I think she would have done well.
Norman Porter, Canada
This result is important for democracy on the island as it is always healthy when an opposition party wins. The opposition (apparently the winner) now has a real commitment to fulfil to the Jamaican people, especially pre-election promises of free education and health care.
Maurice, Mandeville, Jamaica
The speech of Mrs Portia Simpson-Miller was not well received by Jamaicans. In such a tense situation a calming voice was needed, and that only came from the opposition leader when he finally reached his party headquarters. The closeness of the election result may eventually lead to a coalition government, a complete novelty in the bipartisan political landscape of the Caribbean.
John Townend, Kingston, Jamaica
This result is a good one. We hope it will force the parties to work together to solve the country's crime problems and slow growth.
Richard, Kingston, Jamaica