Security forces discovered and disarmed an explosives-laden car parked in front of the main offices of the Guatemalan prison service in the center of this capital, authorities said Monday.

The car bomb was left in front of the building in the wee hours and was meant to be detonated by remote control, Interior Minister Carlos Menocal told reporters.

The attempted attack was probably in reprisal for the recent transfer of jailed gang members to maximum-security prisons, he said.

Inside the vehicle, which had been reported stolen a week ago, was a metal box packed with gunpowder, fireworks and propane-gas cylinders along with a cell-phone detonator, the minister said.

“It’s a mega-bomb that if detonated would have caused serious damage,” Menocal said, “because while all its components are homemade devices, together they have great potency.”

Investigators suspect the car bomb was the work of gangs angry about the steps authorities are taking to isolate jailed gang members and prevent them from directing criminal activity while behind bars.

Eight Guatemalan prison service employees have been murdered in the past year. EFE