Voters in the western African country of Liberia are casting their ballots on Tuesday to elect a new head of state as current President Ellen Johnson Sirleaf prepares to step down after 12 years in power.

Polls opened at 8:00 a.m. (0800 UTC) and will close at 6:00 p.m. (1800 UTC). Around 2.2 million people are registered to vote in the country of 4.1 million.

The first official results are expected within 48 hours after polls close. If no candidate manages to win 50 percent of the vote, a runoff election will take place on November 7.

Read more: Liberia elections: 'Infrastructure key for progress'

Tuesday's election will mark the first time in 73 years that a democratically-elected president will peacefully hand over power to a successor chosen by Liberian voters.

Twenty candidates are running to replace Sirleaf, Africa's first elected female leader, who is stepping down after a maximum two terms in office.

"The future of the country is in your hands, no one is entitled to your vote, not because of party, ethnicity, religion or tribal affiliation," Sirleaf, a co-winner of the 2011 Nobel Peace Prize, said in a speech on Monday.

In addition to the presidential race, Liberians are also set to elect 73 members of the House of Representatives out of 1,000 possible candidates on Tuesday.

Read more: Liberia after Ellen Johnson Sirleaf

Football star and vice president among frontrunners

Although there are several names on the presidential ballot, analysts have said four candidates have a strong chance of winning.

Vice President Joseph Boakai of the ruling Unity Party (UP) is one of the contenders along with former international football star George Weah who is heading up the main opposition Coalition for Democratic Change (CDC).

Other top presidential candidates include longtime opposition figure Charles Brumskine who heads the Liberty Party (LP) as well as former Coca-Cola executive Alexander Cummings.

Many of the candidates campaigned with platforms focusing on creating jobs, fighting corruption and boosting Liberia's economy.

Consecutive civil wars from 1989-2003 and the Ebola crisis from 2014-2016 have left Liberia one the world's poorest nations.

Alongside the results of Tuesday's election, the international community will be looking forward to seeing Liberia's history of assassinations, coups and exiled dictators shift to more stable footing as Sirleaf peacefully transfers her post.

The last peaceful transfer of power between democratically-elected presidents in Liberia took place in 1944 when former President Edwin Barclay handed over power to William Tubman.

rs/kms (AP, AFP, dpa)