Declerations of war are irrelavent to if its an armed conflict (in general declerations of war are obsolete in international law. They might have meaning domestically but do not have meaning in international law).

From what i understand there are two requirements

- the violence has to be intense enough. I think we are there

- the other side has to be an organized armed group capable of conducting warfare. This is the part that seems to be a stretch. The drug runners may be organized but are they really capable of conducting warfare? The quote i found from the red cross is: "Non-governmental groups involved in the conflict must be considered as "parties to the conflict", meaning that they possess organized armed forces. This means for example that these forces have to be under a certain command structure and have the capacity to sustain military operations."