Why 'train surfers' in Jakarta dodge concrete balls

Every day, nearly half a million people commute to Jakarta from satellite cities, many of them sitting on top of trains.

Officials say 11 people were killed while travelling on train roofs last year, and railway staff have started hanging concrete balls just above carriage-height to discourage the practice.

Commuters say that the rising cost of living and overcrowded trains are forcing people to resort to these desperate measures.

Video produced by BBC Indonesian's Ervan Hardoko and Sigit Purnomo.