The discovery of a firebomb on rail tracks in Berlin has increased fears of renewed attacks by left-wing groups in Germany.<br /><br />Security at railway stations has been stepped up following the discovery of the sixteenth explosive device in in nine locations in less than a week.<br /><br />Hundreds of trains have been delayed because of partial shutdowns, but there have been no injuries.<br /><br />A previously unknown leftist group claimed responsibility for the bomb, saying they were protesting against Germany's military involvement in Afghanistan and the country's role as an arms exporter.<br /><br />Al Jazeera's Nick Spicer reports from Berlin.
