Palo Alto Police HQ evacuated after someone dropped off Vietnam War-era grenades

The Palo Alto Police headquarters had to be evacuated on Tuesday after someone dropped off Vietnam War-era grenades and other ammunition for disposal, police said. 

Streets surrounding the Palo Alto Police headquarters were cordoned off as the bomb squad investigated. 

Palo Alto Police later determined that the grenades were "training grenades,"  and lifted the evacuation order.