Liberian officials on Thursday are expected to announce the preliminary results of the country's hotly-contested presidential election.

President Ellen Johnson Sirleaf held an early slight lead over her main rival Winston Tubman in unofficial polling data released Wednesday by the independent Liberia Media Center.

The Monrovia-based organization said it compiled the data from tallies posted at various polling centers across the West African country.

Liberia's National Elections Commission says final results will not be announced until October 26. A second round of elections will be held if no candidate wins more than 50 percent.

Liberians also voted in legislative elections Tuesday. It was the country's second national elections since the end of a 14-year civil war in 2003.

A top official of the U.S.-based Carter Center says the commission did an “exemplary” job organizing the elections.

John Stremlau tells VOA that Carter Center election monitors were concerned about some of the rhetoric during the campaign, but saw dedication from poll workers and great patience from voters on Tuesday.

Mrs. Sirleaf is facing a tough fight for a second term, just days after receiving the Nobel Peace Prize.

Critics have questioned the timing of last Friday's announcement of the Nobel prize, which President Sirleaf won along with two other women. They say it could provide her with an unfair boost.