Three US soldiers have been killed in a bomb blast as they attended a girls' school re-opening ceremony, which was destroyed in a previous attack.

The US servicemen, who were killed on Wednesday in the Lower Dir district in Pakistan's restive North West Frontier Province, are considered to be the first American fatalities in Pakistan's lawless tribal regions.

They were also among 60 to 100 members of a Special Forces Operation team that trains Pakistan's paramilitary troops in counter-insurgency techniques.

Al Jazeera's  Nicole Johnston reports.

Source: Al Jazeera