Gunmen in Pakistan kidnapped the brother of Afghanistan's finance minister while he was walking to his mother's home after praying at a mosque, Afghan officials said Sunday.

Zia ul-Haq Ahadi was abducted in the Pakistani city of Peshawar on Friday, said Haziz Shams, the spokesman for Afghanistan's Finance Ministry. The kidnapped man's brother is Finance Minister Anwar ul-Haq Ahadim.

Shams said it isn't known who kidnapped Ahadi. No demands had been made, and the kidnappers have not contacted officials or the Ahadi family, he said.

Ahadi is a businessman who lives in Afghanistan and was in Peshawar to visit his mother, who is ill, said Abdul Razaq, an assistant to the finance minister.

Ahadi was walking home after Friday prayers at a neighborhood mosque when he was taken, Razaq said.

In February, Taliban gunmen kidnapped Pakistan's ambassador to Afghanistan on the main highway between Peshawar and the Afghan-Pakistan border. He was freed after three months in captivity.

In September, gunmen ambushed a car carrying Afghanistan's ambassador-designate to Pakistan, Abdul Kahliq Farahi. A Foreign Ministry official said Sunday that Farahi was still being held.

Kidnappings in Afghanistan have spiked in the last year because criminal groups have found them to be lucrative because of the ransoms usually paid by families and companies for hostages.

Meanwhile, U.S. troops with the NATO-led International Security Assistance Force shot and wounded five Afghan army soldiers in eastern Kunar province Sunday. The troops had fired on what they thought were militant forces, a NATO statement said.

The wounded Afghan soldiers were evacuated to a medical facility, it said.

"It is with deep regret that this incident has taken place; we have initiated an investigation to determine how this happened and how to prevent any future occurrences," said Col. John Spiszer, a U.S. commander. "We have the utmost respect for our Afghan partners and value their relationship with ISAF."