BAGHDAD — Iraqis passed through security checkpoints and razor wire cordons to vote today in provincial elections that are considered a crucial test of the nation's stability as U.S. officials consider the pace of troop withdrawals.

Polls opened shortly after dawn after a step-by-step security clampdown across the country, including traffic bans in central Baghdad and other major cities and closure of border crossings and airports.

More than 14,000 candidates, including about 3,900 women, are running for 440 seats on the influential councils in all of Iraq's provinces except for the autonomous Kurdish region in the north and the province that includes oil-rich Kirkuk, where ethnic groups were unable to reach a power-sharing formula.

Voters headed home waved their purple-tinted index fingers, which are dipped in ink to identify people who already cast ballots. The ink-stained fingers became an iconic image of Iraq's first post-Saddam Hussein elections four years ago.

Preliminary results are not expected before Tuesday.