Gunmen in northern Afghanistan's Takhar province kidnapped a Dutch aid worker and his Afghan driver Monday.

A spokesman for the provincial governor said the two were working for an aid group helping the disabled.   

Dutch officials confirmed the kidnapping, but gave few details.  The foreign ministry said the Dutch embassy in Kabul is in contact with Afghan authorities to bring the matter to a "positive conclusion."

Afghanistan has become increasingly dangerous for aid workers. In August, 10 members of a Christian medical team were killed in northern Badakhshan province.  Earlier this month, a British aid worker abducted by militants in eastern Afghanistan was killed during a rescue attempt.

Also Monday, NATO said 15 militants were killed in an overnight Afghan-NATO operation against a senior Taliban leader in southern Helmand province.

NATO said the joint force called in an airstrike after ensuring no civilians were in the area.  But provincial officials say 25 people, including civilians, were killed in the airstrike. Local residents say a mosque was also destroyed during the operation.

In eastern Khost province, a suicide bomber detonated explosives at a police checkpoint Monday, killing three people, including a police officer.  Afghan and coalition forces in the province also destroyed a compound rigged with explosives.

In neighboring Paktika, a joint Afghan-NATO force killed a leader of a Taliban cell and two other insurgents.

Another suicide bomber targeted a foreign troop convoy in the capital of northern Baghlan province, Pul-e-Khumri, Monday.  Officials say the attacker was killed, but no one else was injured in the blast.

In southern Helmand and Kandahar provinces, Afghan and coalitions forces seized 1,400 kilograms of opium, along with several automatic weapons.

Also Monday, Afghan President Hamid Karzai reaffirmed his decision to bar private security firms from operating in Afghanistan, but added that reconstruction efforts and aid delivery will not be affected by the ban.

Some information for this report was provided by Reuters.