'You aren't going to solve these problems by closing borders'

The UN refugee agency is warning of a `"build-up'' of migrants in Serbia as its neighbours tighten their borders.

It is not a crime to cross a border to seek asylum - info from @Refugees is here: http://t.co/MhwC4jtW1E pic.twitter.com/sOilzkGI0h

— United Nations (@UN) September 18, 2015