KABUL, August 20 (RIA Novosti) - Incumbent Afghan President Hamid Karzai said more than 70 militant attacks occurred in almost half of the country's provinces during presidential elections on Thursday.

Polls to elect a president and provincial council members started in Afghanistan early on Thursday, with a low turnout expected due to a series of attacks by Taliban militants in the capital.

Karzai said during a press conference that 15 of the 34 Afghan provinces saw militant violence attacks throughout the day.

Tolo television reported that many polling stations were closed in the north-central province of Baghlan due to heavy fighting that killed 22 Taliban insurgents and injured another 20. Three security officers were also killed in the conflict.

Taliban leaders have condemned the elections, and threatened to disrupt voting across the country. Three insurgents were shot dead by Afghan security forces on Thursday morning after entering a bank with explosives.

The presidential election is the second since the U.S. military ousted the Taliban in 2001.

Of 30 presidential candidates, the incumbent Afghan leader Hamid Karzai leads opinion polls with around 45% of support. His two main challengers are former foreign minister Abdullah Abdullah and former finance minister Ashraf Ghani.

The Central Election Committee has just begun counting ballots.

In a national address, Karzai earlier urged people to vote "for the sake of the happiness and prosperity of the motherland." He played down the Taliban's threat to disrupt voting.

The Afghan electoral authority told RIA Novosti that around 7,000 polling stations would be opened throughout the country, home to around 25 million people. The polls are being monitored by 21 local and 30 foreign observers.