Two children who were abducted at gunpoint in Philadelphia on Thursday night have been found safe, following an AMBER Alert. 

The two children, aged 3 and 4 were taken after an armed 'altercation' at a Lancaster residence on Thursday night.

Police say the children's father, 23-year-old Eddie Ahorrio jr. and grandfather, 47-year-old Eddie Ahorrio sr., abducted the children at gunpoint and fled in a black Nissan, heading towards Massachusetts or New Jersey.

The AMBER Alert was cancelled shortly after the car was stopped.  

AMBER Alert was created after the abduction and murder of 9-year-old Amber Hagerman in Texas.  After her murder, her mother lobbied extensively to have laws changed regarding sex offenders, including the creation of a national sex offenders registry.  

The AMBER Alert works in the same way as a police APB, but is directed towards the general public.  Details are broadcast on commercial and inter radio, LED traffic weather signs on highways, through emails, television and cable television.  The ALERT is put in place.  Canada, Mexico, places in the EU, the UK and Queensland, Australia have implemented a similar system.

Amber's homicide remains unsolved, but the measures put in place after her death have contributed to saving countless lives.