Story highlights U.S. Embassy says the attack only hardens its resolve to work with Afghans for peace

Afghan President Hamid Karzai condemns the attack

Blast also kills the provincial head of the Afghan intelligence service

"We suspect it is the Taliban who are enemies of Afghanistan," a police official says

A lone suicide bomber detonated a vest filled with explosives at a wedding in northern Afghanistan on Saturday, killing at least 17 guests, including a top politician, authorities said.

There were conflicting reports on the casualties. Police said 22 people died and about 40 were wounded in the attack.

Afghan President Hamid Karzai, who condemned the attack, said it killed 17 people and wounded 43 others.

The attacker's blast tore through the wedding hall in Aybak, capital of Samangan province.

Fatalities included Ahmad Khan Samangani, who was a member of the Afghan parliament. He was killed as he hosted his daughter's wedding, said Lal Mohammad Ahmadzai, a police spokesman.

Samangani also served as a militia leader during the Afghan civil war and fought against the Taliban.

The attack seemed to target him as he welcomed guests at the entrance to the hall, police said.

The provincial head of the Afghan intelligence service was also killed at the wedding attended by prominent security and military officials from the area.

"There has been no claim of responsibility so far," Ahmadzai said. "We suspect it is the Taliban who are enemies of Afghanistan."

The U.S. Embassy in Kabul condemned the attack, which it said killed more than 20 people, "in the strongest terms."

"We extend our condolences to the families of Samangani and Khan, and to the families of all victims of today's attack," it said in a statement. "This attack will only harden our resolve to work together with the Afghan government and people to realize a peaceful and prosperous Afghanistan."

Samangani was elected to parliament during the troubled 2010 poll.

Electoral officials at first ruled he had been unsuccessful, but his supporters blocked roads through the province in protest. He was eventually awarded a seat in Afghanistan's lower house on appeal.

A number of top security officials have been assassinated in northern Afghanistan in the past 18 months.