German police believe a home-made bomb could have caused an explosion at the offices of the hard-left Die Linke political party in western Germany, according to dpa sources. Police in the city of Oberhausen found evidence of a home-made explosive device that was built using “flash explosives” like those contained in fireworks, the sources said. An explosion at around 3:20 am (0120 GMT) destroyed the windows of the Die Linke party office. It also partially destroyed the interiors of the shops including a hairdressers and a travel agent. Yusuf Karacelik, parliamentary group leader of the party i…