Four people have been killed and 16 wounded in a bomb attack on a newly opened Colombian drug-rehab centre which police believe was the work of organised crime.
Initial reports said the attack, in Medellin, involved "around a kilo of explosives" being carried unwittingly in a bag into the centre by one of its residents, who died in the blast.
AAP reports the authorities believe the bomb was likely activated via a telephone.
Investigators said the attack was orchestrated by drug dealers riled by the rehab programme, which offers voluntary treatment to down-and-out addicts.
