People in Afghanistan have voted in key parliamentary elections amid threats from the Taliban, who had vowed to disrupt the vote.Six security force members were killed in a Taliban attack in the north, and at least five people were killed in other attacks across the country, BBC reports.

The head of the election commission put turnout at 32% by midday. There have also been some reports of fraud.

The poll is seen as a test of credibility for President Hamid Karzai.

More than 2,500 candidates are vying for 249 seats in the lower house of parliament, or Wolesi Jirga.

Afghan soldiers and police have been on alert, backed up by nearly 150,000 foreign troops.

Polls closed at 1130 GMT in the first vote since a fraud-marred presidential election last year.

Faizal Ahmad Manawi, head of the Independent Election Commission (IEC), said that by midday figures from 2,627 polling centres had shown that 1,689,457 people had voted.

"If this doubles - though I believe it will be more than double - it will have been a success," he said.

Manawi said that about 8% of the more than 5,800 polling stations expected to open had not done so or had not reported in, mostly as a result of security problems. Another 1,000 polling stations were earlier ruled out due to security.

There are more than 10 million registered voters, but the UN says a turnout of five to seven million would be a success, given the difficulty of holding a poll in the middle of a war.

A Nato spokesman told Agence France-Presse news agency there had been fewer incidents of violence than in last year's presidential poll. He said 303 incidents had been recorded by the time polling ended, compared with 479 on 19 August last year.

The Taliban had earlier warned voters to boycott the poll and "stick to jihad".

In what correspondents said was a thinly-veiled threat, the Taliban said it had "chalked out certain measures... to frustrate this American process and will implement them on the day when the illegitimate process of elections is conducted".

The Taliban had claimed responsibility for kidnapping two parliamentary candidates and 18 poll officials and campaign workers in the run-up to the elections.