Voters went to the polls Thursday to choose the city's next mayor from among 10 candidates, including incumbent Kenneth Livingstone. Besides naming their top two mayoral choices, voters also will vote for the 25 members of the London Assembly, the BBC reported.

If a candidate receives more than half of first-choice votes, he or she is elected mayor, election officials said. If the top vote-getter has less than half, the top two "first-choice" candidates advance to a second round of voting.

London has 5.5 million registered voters eligible for the mayoral election.

Elections also were being conducted in Camden, Ealing, Hammersmith and Fulham, and Tower Hamlets, the BBC said.

Barnet election officials said five polling stations didn't receive paper ballots by the time the polls opened Thursday because of computer problems, the BBC report said.

"Unfortunately, a handful of polling stations did not receive their ballot papers until some minutes after (polls opened) and we sincerely apologize to those voters affected," the Barnet Council said in a statement.