Afghanistan - A suicide bomber on a motorcycle detonated his explosives in a crowded area in southwest Afghanistan on Friday, killing 17 people, including a senior police official, a provincial governor said.

Farah Province Police Chief Faqir Mohammad Askar said the target of the attack in the provincial capital Farah City was the police official, who was killed along with two of his bodyguards.

Governor of Farah, Rohul Amin told Reuters the death toll in the blast had risen to 17. Earlier, the head of the city's main hospital, said 15 people had died. Amin said 29 people were also wounded in the attack.

Taliban spokesman Qari Yousuf telephoned Reuters from an undisclosed location and denied his group had carried out the Farah raid.

Whenever there are civilian casualties, the Taliban deny responsibility, said Farah Governor Amin. This attack was definitely carried out by the Taliban.

Violence in Afghanistan has reached its highest levels since the U.S.-led invasion in late 2001. While Taliban militants normally target foreign and Afghan security forces in their attempt to overthrow the government and drive international troops out of the country, most of the casualties are civilians.

Some 1,500 civilians were killed between January and August this year, according to the United Nations.

The latest attack comes a day after President Hamid Karzai was sworn in for his second five-year term in a ceremony attended by dozens of foreign dignitaries.

In his inaugural speech, Karzai said he wanted Afghan forces to take the lead from international military forces in securing the whole country. There are some 110,000 foreign troops, including 68,000 U.S. soldiers, in Afghanistan.

U.S. President Barack Obama is due to give a decision in the next few weeks on whether to send up to 40,000 more troops that his top commander in Afghanistan, Army General Stanley McChrystal, says he needs to quell the strengthening insurgency.

Farah, a mainly desert province along the border with Iran, is one of the areas that has seen a rise in insurgent attacks this year as Taliban militants have spread to the west and north from their traditional bases in the south and east.

The NATO-led force in Afghanistan confirmed the Farah incident, but said no Western troops had been in the area at the time of the attack.

(Writing by Jonathon Burch and Peter Graff; Editing by Alex Richardson)