Vote counting continues in Liberia, after a presidential run-off that was boycotted by the challenger, leaving President Ellen Johnson Sirleaf poised to win a second term.

Observers reported very low turnout Tuesday, sparking concerns that opposition supporters will reject the outcome and that political violence will erupt.

Opposition candidate Winston Tubman of the Congress for Democratic Change dropped out of the poll after accusing the electoral commission of fraud. On Wednesday, Mr. Tubman made clear he will not accept the results, which are expected by the end of the week.

Meanwhile, the Liberian government is standing by its decision to close three radio stations believed to be sympathetic to the opposition, including one owned by Mr. Tubman's running mate. The government charged they were broadcasting hate speech and inciting violence.

The government shut down the radio stations on Monday, after clashes between police and opposition supporters in Monrovia killed at least two people.

In an interview with VOA, Liberia's deputy information minister said the move was necessary to maintain the country's stability.

Earlier, the U.S. State Department said it is “deeply disappointed” at Mr. Tubman's decision to boycott the election, saying claims of voter fraud are unsubstantiated.

President Sirleaf, Africa's first democratically elected female leader, handily won the first round of voting last month, but fell short of the majority needed to avoid a run-off.

Election observers said the first round of voting was generally free and fair.

This is Liberia's second presidential election since the end of the country's civil war in 2003. Mrs. Sirleaf won the Nobel peace prize this year for helping Liberia recover from the war.