Blasts in Karachi and Peshawar and gun battle in Chaman leave at least 22 dead and scores more wounded

At least 22 people have been killed in bomb attacks and gun battles in Pakistan as millions of voters turned out despite the threats of violence in landmark national and provincial elections.

A bomb attack in the port city of Karachi on Saturday morning targeted the office of the Awami National party (ANP), killing 10 people and wounding more than 30, according to Reuters. Local media also reported gunfire in the city, underlining the range of risks faced by the country's 86 million voters.

A roadside bomb in Karachi also killed one person riding in a bus of ANP supporters. In the north-western city of Peshawar a bomb outside a polling station killed one person while two more died when a bomb went off near a police van.

In the south-western province of Baluchistan, gunmen killed two people outside a polling station in the town of Sorab and a shootout between supporters of two candidates in the town of Chaman killed six people, officials said.

The violence follows a string of bombings and shootings by the Taliban, which have marred the runup to the elections and claimed the lives of more than 130 people.

The historic vote, which pits a former cricket star against a two-time prime minister and an unpopular incumbent, marks the first transition from one civilian government to another in a country ruled by the military for more than half of its history.

Pakistan's Taliban, who regards the elections as un-Islamic, have focused their violent campaign on secular-leaning parties, such as the ruling coalition led by the Pakistan People's party (PPP) and the ANP.

In response to the threat, the government has deployed an estimated 600,000 security personnel across the country to protect polling stations and voters.

"Yes, there are fears. But what should we do? Either we sit in our house and let the terrorism go on, or we come out of our homes, cast our vote, and bring in a government that can solve this problem of terrorism," Ali Khan, a voter in Peshawar, told the Associated Press.

Disillusionment with the two main parties appears to have brought a late surge of support for the former cricket star Imran Khan, who analysts predict could end up holding the balance of power. Khan, 60, who is in hospital after injuring himself in a fall at a party rally, is facing off against the Pakistan Muslim League-N, headed by the two-time former prime minister Nawaz Sharif, and the PPP, led by the president, Asif Ali Zardari.

Khan has won support by tapping into the frustrations of millions of Pakistanis eager for a change from the political establishment who have long dominated the country's political scene.

"The team that we elect today will determine whether the rot will be stemmed or whether we will slide further into the abyss," the prominent lawyer Babar Sattar wrote in The News daily.

"I never voted for anyone in the past, but today my sons asked me to go to polling station, and I am here to vote," said Mohammed Akbar, speaking from the north-western city of Khar. "Imran Khan is promising to bring a good change, and we will support him."

On the campaign trail, Sharif has painted himself as having the experience needed to tackle the country's problems.

"It's better to try a lesser evil instead of trying a novice," said Haji Mohammad Younus, a voter in Lahore. "The lesser evils at least have the experience of governing. They might be corrupt but they have lately realised that they have to deliver if they want to survive."

"The problems facing the new government will be immense, and this may be the last chance that the country's existing elites have to solve them," said Anatol Lieven, a professor at King's College London and author of a book on Pakistan.

"If the lives of ordinary Pakistanis are not significantly improved over the next five years, a return to authoritarian solutions remains a possibility," Lieven wrote in a column in the Financial Times.

Results from nearly 70,000 polling stations nationwide are expected to start tricking in from around 10pm local time (5pm GMT).