Schengen: Europe's passport-free travel zone 'on brink of collapse'
The system that allows passport-free movement across Europe is feared to be on the brink of collapse as nations tighten their border controls because of the refugee crisis.
European Council president Donald Tusk has admitted it is a "race against time" to save the Schengen travel zone, which has operated for 30 years.
The council president spoke before another informal summit in Valetta dedicated to the issue of Schengen and urged: "We must hurry, but without panic."