Two Afghans were killed and 17 wounded in the attack in Herat.
A confidence building measure ahead of possible peace talks.
Authorities are investigating which militant group was involved in the attack in the Khyber tribal area.
Ahmad Shah Massoud was slain two days before the Sept. 11, 2001 attacks.
Brings total released to 33; meant to further Afghan peace process.
Militants have targeted prominent women several times recently.
NATO service member killed separately in east.
Ten others wounded as insurgents ambushed convoy.
No reports of coalition casualties; officials say 10 insurgents killed.
Afghans fearful of foreign withdrawal, despite assurance new home-grown force can protect them.
