Deadly blasts have rocked Pakistan, killing more than a dozen people as voting began in the country's landmark elections.

At least three cities have been struck by explosions and gunfire targeting secular political outfits.

Local reports say there have been at least three blasts in Pakistan's commercial capital Karachi, and two explosions elsewhere in the country.

Officials have confirmed that at least 11 people have been killed in the blasts in Karachi and scores of others have been injured. The explosions are said to have targeted the Awami National Party.

The Pakistan Taliban has claimed responsibility for the attack. "We proudly claim responsibility for this attack, we carried it out and will carry out more of the same," said Ehsanullah Ehsan, a spokesman for the Islamic militant group, according to local reports.

Another bomb attack in the city of Peshawar wounded at least eight people. "The bomb was planted on a motorcycle. Several people including police have been injured. The motorcycle was parked outside a women's polling station," said a senior police official.

The Al-Qaida-linked Taliban had earlier threatened to carry out attacks during the elections as they consider the democratic process "un-Islamic". Despite the threat, millions of Pakistani citizens have voted.

"Bombs or terrorist attacks must not stop voters from using their right to vote. People will have to decide what kind of Pakistan they want. If they vote for the wrong party, they will suffer for another five years," a 70-year-old voter, Humayon Qaiser, told the Associated Press.

More than 130 people have been killed in the run-up to the election. Nearly 75,000 troops have been deployed across the country to counter the Taliban threat.

The result of the election will determine the first transfer of power from one civilian government to another in Pakistan's turbulent 66-year history.