GUATEMALA CITY — Police in Guatemala City found a car packed with  gunpowder, nails and propane tanks parked outside the national prison  headquarters Monday, along with cellphones apparently designed to  detonate the load.
Police specialists deactivated the devices without incident.
It  is apparently the first car bomb attack attempted by Guatemalan  criminals in recent memory. In neighbouring Mexico, drug cartels have  started using such bombs; four have gone off there since July, mainly  targeting police.
Guatemalan Interior Minister Carlos Menocal said  the incident may be related to street gangs' anger over a recent  government decision to transfer gang members.
Menocal said a guard  noticed the car parked outside the prison office, and when he looked  inside he saw wires connecting the gas tanks to a large metal box.
The  alert was sounded and when specialists defused the device and looked  inside the box, they found it was packed with gunpowder, nails and  screws apparently intended to spread projectiles over the blast area.
The device appeared to be "homemade but of large dimensions," Menocal said.
While  Guatemala has not seen car-bombings before, street gangs have been  blamed for six grenade attacks on public buses that killed 3 people and  wounded 55.