Afghanistan Rickshaw Suicide Bomber Kills 15

At least 15 people have been killed and dozens injured after a suicide bomb attack at a market in northern Afghanistan.

There was no immediate claim of responsibility for the attack in Maimanah, the capital of Faryab, a remote province that borders Turkmenistan and has a mixed population of Uzbek, Turkmen and Pashtun ethnic groups.

Provincial governor Mohammadullah Batash said the bomber targeted the Tuesday bazaar, adding: "The blast happened on the main roundabout, which was very crowded.

"The bomber used a three-wheeler packed with explosives. All 15 of the dead are civilians or street vendors, and at least 27 are also wounded."

Toryalai Adyan, the provincial police chief, and hospital officials gave a similar account and death toll.

Northern Afghanistan is generally more peaceful than the south and east of the country, but Islamist insurgents, rival militias and criminal gangs are active in some districts.

Security has been stepped up ahead of the presidential elections on April 5.

Last week, the Taliban urged its members to attack polling staff, voters and security forces.

Jan Kubis, the United Nations envoy to Kabul, said he was "gravely disturbed" by the Taliban threat to unleash a "campaign of terror".

Previous Afghan elections have been badly marred by violence, with at least 31 civilians and 26 soldiers and police killed on polling day in 2009, as the Islamist militants displayed their opposition to the US-backed polls.

President Karzai, who is barred from serving a third term in office, has consistently said Afghanistan will hold a safe and clean election, despite previous violence and allegations of massive fraud when he won the last poll five years ago.