KABUL, Afghanistan – Insurgents have kidnapped a parliamentary candidate and at least 18 election workers, Afghan officials said Friday, raising fears on the eve of an election that has emerged as a test of wills between the Afghan government and the Taliban.

Insurgent leaders have urged voters to refrain from voting in today’s election, the third major vote in Afghanistan’s short and troubled history as a democracy. They have declared candidates and campaign workers legitimate targets for assassination and have threatened to cut voters’ ink-stained fingers.

Amid growing violence and deepening skepticism in the United States and NATO capitals about the strategy in Afghanistan, the vote will be a key test for the Afghan government after last year’s fraud-plagued presidential election.

Since his reelection last year, President Hamid Karzai has faced growing criticism at home and abroad over rising insecurity and rampant corruption.

The stakes are high for the U.S., which is trying to persuade Afghans to back their government despite deepening doubts that the state will hold as the U.S.-led international force begins to thin out next year.

The Free and Fair Election Foundation of Afghanistan, one of the country’s main election monitors, has called this election season the most violent since the Taliban regime was toppled in 2001.

The 19 reported kidnappings Thursday and Friday were the latest in a string of incidents that have soured voters’ mood.