FACTBOX: What next in Zimbabwe's political crisis?

(Reuters) - Below are answers to some questions on Zimbabwe's political crisis as voters cast their ballots in an election on Friday in which President Robert Mugabe is the only candidate.

Opposition leader Morgan Tsvangirai withdrew from the run-off six days ago, saying violence by Mugabe's supporters meant it could not be fair.

WHAT HAPPENS NOW?

Voting ended with initial indications that the turnout was lower than in the first round of voting on March 29. Tsvangirai has accused Mugabe of forcing Zimbabweans to vote but said millions had not voted despite intimidation.

State television denounced foreign media reports of low turnout. It showed long queues in a semi-rural constituency close to Harare and said voters ignored MDC appeals to abstain.

Mugabe is virtually guaranteed to win the contest and the 84-year-old Zimbabwean leader would then be sworn in for another five-year term.

Tsvangirai beat Mugabe in the first round of voting, but according to official figures fell short of the outright majority needed to avoid a run-off.

WHAT HAPPENS AFTER THE ELECTION?

Zimbabwe's government says the winner of the election will be sworn in soon.

Tsvangirai has said if Mugabe goes ahead with the election and declared himself president, he would be shunned as an illegitimate leader who killed his own people.

Governing the country may be tricky for Mugabe because the opposition won control of parliament in the March 29 general election. Mugabe's ruling party has challenged some of those results. The presidency is also a powerful institution.

WHAT IS THE IMPACT ON ZIMBABWE AND SOUTHERN AFRICA?

The prospects of reversing Zimbabwe's economic meltdown are slim without a change in government. Mugabe refuses to consider reforms and Western powers are unlikely to provide the billions of dollars in development aid needed to bail out the economy.

Zimbabwe's neighbors could be swamped with an even bigger influx of refugees.

An estimated three million Zimbabweans are in South Africa, where there are rising anti-immigrant feelings. More than 60 African migrants were killed in recent attacks by mobs there.

Investors keen to invest in Zimbabwe will keep plans on hold despite a widespread belief that the once-prosperous economy could bounce back quickly under a new government.

HOW WILL AFRICA AND THE WORLD REACT?

The 14-nation SADC is under increasing pressure to help settle the crisis.

The African Union will discuss Zimbabwe at a summit in Egypt which began on Friday. Mugabe has said he will attend the AU summit where heads of state meet from Monday.

Diplomats at U.N. headquarters in New York said it was possible the Security Council would call an emergency meeting over the weekend if the election goes ahead and Mugabe declares himself the winner.

G8 nations lambasted Zimbabwe on Friday and the United States said the U.N. Security Council may consider fresh sanctions on the African country next week.

Military intervention by SADC or the African Union is not seen as an option. Any such move is likely to face strong opposition from South Africa, the regional political and economic powerhouse.

WILL THERE BE MORE VIOLENCE?

Tsvangirai has sought refuge at the Dutch embassy since Sunday, fearing for his safety.

The MDC and trade unions could take to the streets to protest against Mugabe's government, but that would probably prompt a heavy backlash by well-equipped security forces. Tsvangirai and other MDC officials were beaten in an aborted March, 2007 rally.

COULD THERE STILL BE NEGOTIATIONS?

Although Tsvangirai has said he would not negotiate with Mugabe if the vote goes ahead, he could still be under pressure to do so from some quarters.

South African President Thabo Mbeki has urged the two sides to hold talks. South African media had reported Mbeki, who has mediated the Zimbabwe crisis for more than a year, favored the formation of a unity government. The idea has not taken off.

HOW LONG WILL MUGABE STAY IN POWER?

Mugabe has said he wants to stay on until he is sure that it is impossible to reverse a land redistribution program that saw thousands of white-owned farms seized and given to poor blacks -- one of the policies blamed for Zimbabwe's collapse.

Some believe that victory in the election could allow him to bow out sooner rather than later, by departing from a position of strength in favor of a hand-picked successor, and with the opposition in disarray.

(Reporting by Harare and Johannesburg bureaux; Editing by Matthew Tostevin)