Police in Bosnia and Croatia have arrested 38 people accused of smuggling illegal migrants into the European Union in a coordinated crackdown on human trafficking in the region. _0"> The so-called "Balkan smuggling route" is used to ferry contraband drugs and people from Eastern Europe, Africa and the Middle East. Police in Croatia, which joins the European Union on July 1, arrested 25 people and were looking for eight more suspects, while 13 were arrested in Bosnia, said Dean Savic, head of the Croatian police unit for corruption and organized crime. "This is a message to the smugglers - rest assured we'll come knocking on your door," Savic told a news conference. In preparation for EU entry, Croatia has almost tripled the number of border police to around 6,000. They will patrol its 1,400-km land border with non-EU neighbors Serbia and Bosnia, equipped with thermal vision cameras and infrared binoculars that can spot illegal migrants at night.