Spain's defense minister says a helicopter crash that killed 17 Spanish troops in Afghanistan could have been caused by hostile fire.

Jose Bono says officials have not determined what brought down the helicopter carrying Spanish members of the NATO-led international security force in Afghanistan.

He says the pilot of a second Spanish helicopter saw smoke from the ground, and thinking there was an attack, made an emergency landing, wounding five soldiers. Rescuers are at the site near Herat, recovering the dead and wounded.

Afghan officials say the crash could have been caused by an accident or bad weather.

Some information for this report provided by AP and AFP.