Two international aid workers - a Canadian and a Bangladeshi - who were kidnapped in Afghanistan three days ago have been liberated by security forces, the AIP news agency said Friday.

The workers were freed on Thursday afternoon, the governor of Bamiyan province, Habiba Surabi, told AIP.

Four suspected kidnappers have been detained, Surabi said.

The kidnapping took place on Tuesday near Bamiyan city, the provincial capital.

No group has claimed responsibility for the abduction, and security officials said it was probably the work of hostage takers since the area is not a stronghold of the insurgency.

The two foreigners were in Afghanistan with the Aga Khan Development Network, an international organization that does humanitarian work in developing countries.

Bamiyan is a province that has been relatively unaffected by the ongoing war. It is inhabited largely by Hazaras, a Shi'ite Muslim people of Central Asian origin who were persecuted by the Taliban.

On Aug. 8, a Belgian citizen was kidnapped and then released unharmed the same day in the northwestern part of the country.

Kidnappings and violent incidents are a constant occurrence in Afghanistan, although they take place more often in the conflict-ridden southeastern portion of the country.

The NATO-led international forces are scheduled to conclude their gradual withdrawal from Afghanistan next year, coinciding with elections in which voters will choose the successor to President Hamid Karzai.

The Afghan conflict is going through one of its bloodiest periods since the U.S. invasion in 2001 that toppled the Taliban regime. EFE