KABUL, Afghanistan (AP) — Afghan voters filed more than 2,500 complaints of ballot box stuffing and other election irregularities, an official said Tuesday, as fraud allegations by the two candidates and their supporters threaten to provoke a new political crisis.

The campaign tone has been sharply more accusatory than that of the first round of voting on April 5, when Afghans had eight candidates to choose from and all promised to adhere to the results released by the Independent Electoral Commission.