HAMILTON, Canada

Polls opened Tuesday morning across California for closely watched special elections that will fill several vacant state and local offices.

According to the California Secretary of State's Office, polling stations opened at 7 am local time (1500GMT) and will remain open until 8 pm (0400GMT Wednesday). Local officials said more than 2 million ballots had already been returned in the most populous US state ahead of Election Day through drop boxes and early voting centers.

Election officials told voters that ballots sent by mail must be postmarked by Tuesday and received by Nov. 12 to be counted. Same-day voter registration is also available at county election offices and vote centers.

While local officials expect the turnout to be modest, they also urged residents to cast ballots early and confirm their polling locations online at sos.ca.gov.

Initial results are expected shortly after polls close, with full certification to follow later this month.