HERAT, Afghanistan (Reuters) -- A roadside bomb attack claimed by the Taliban has killed at least 12 people in west Afghanistan's most important city, officials said, amid worsening security before a presidential poll this month.
The remote-controlled bomb may have been aimed at a local police chief but killed mainly passersby when it went off during rush hour near a blood bank in Herat, a relatively peaceful city near the Iranian border and an important commercial center.
Violence has escalated across Afghanistan before the August 20 presidential poll, seen as a key test for Washington and Kabul. Nine foreign soldiers, including six Americans, were killed in Taliban strongholds in the south and east over the weekend.
The Taliban have vowed to disrupt the election and have called on Afghans to boycott the ballot, the second direct vote for president since the Islamists were toppled in 2001.
Among those killed in the August 3 blast were a woman, a 12-year-old girl, and two policemen, said provincial security commander General Esmatullah Alizai.
A Reuters witness saw several women and children being carried out of ambulances on stretchers into a military hospital in Herat.
Alizai put the death toll at 10 and said Khoja Issa, a district police chief in the area, was also seriously wounded. Taliban spokesman Qari Mohammad Yousuf said Issa was the target of the attack.
Afghanistan's Interior Ministry put the death toll at 10 and said 29 were wounded. Afghan President Hamid Karzai condemned the Herat bombing, labelling it "a terrorist attack."
Herat, one of Afghanistan's three largest cities, is usually a safe and prosperous center because of strong trade links with neighbouring Iran and Turkmenistan.
Deadly Weeks Ahead Of Poll
July was the deadliest month for foreign forces in Afghanistan since the Taliban were ousted in 2001, with at least 71 killed. August has so far followed that deadly trend.
A total of 41 U.S. troops were killed in July, far more than the previous monthly high of 26 in September 2008.
Britain has also suffered its worst battlefield casualties in almost a generation, with the 22 killed in July taking its toll in the eight-year-old war to 191, 12 more than were killed in Iraq.
Attacks across Afghanistan this year had already reached their worst level since 2001. They escalated further after thousands of U.S. Marines launched a major operation in southern Helmand Province last month, long a Taliban stronghold and the source of most of the opium that helps fund the insurgency.
The U.S. operation, along with a similar British offensive, is the first under U.S. President Barack Obama's new regional strategy to defeat the Taliban and stabilize Afghanistan.
Civilians are also dying at record rates. The United Nations said last week 1,013 civilians had been killed between January and June this year, up from 818 in the same period last year.
The Taliban and other insurgents were responsible for 59 percent of those deaths, the United Nations said.
There have also been a series of election-related attacks, with one of President Karzai's campaign convoys ambushed in southeastern Ghazni on August 1. A bodyguard was killed and a candidate for provincial elections was wounded.
Among candidates attacked in the past 10 days were Mohammad Qasim Fahim, Karzai's vice-presidential running mate. Fahim was unhurt. Several campaign offices have also been bombed.
The election is seen as a test for Obama's new strategy, as well as Kabul's ability to stage a legitimate and credible poll.
Karzai is seen as a clear front-runner in a field of 35 challengers. While his main rivals, former Foreign Minister Abdullah Abdullah and former Finance Minister Ashraf Ghani, have been campaigning vigorously, Karzai has been quietly building coalitions among the large field of contenders.
On August 3, he announced Abdul Majeed Sameem, a minor candidate from Jawzjan Province in the north, had become the latest of an original field of 40 challengers to pull out in favor of Karzai.
Poor security appears one of the few threats to the man who has ruled since 2001 and won the first direct vote in 2004.
Low voter turnout in the ethnic Pashtun south, Karzai's power base, could raise the possibility of a second runoff vote if no one gets more than 50 percent in the first round.