A tragic incident in which German soldiers shot dead three Afghan civilian occupants of a car prompted calls in Germany Saturday to pull German troops out of Afghanistan, according to dpa. German prosecutors have begun an inquiry to establish whether the soldiers who opened fire Thursday evening were culpable in any way. The prosecutors from near Berlin said they had sent a request to the Justice Ministry in Kabul that it assist the investigation. Defence officials said German troops had been nervous at the time after one of them had been killed by a suicide bomber this week. A German news website, Spiegel Online, quoted German officers saying a warning had been circulated that an explosive-packed vehicle would be used to attack German troops Thursday evening. The German armed forces said a woman and two children were killed and two children injured when their car accelerated away from a checkpoint at Karuti near Kunduz. The checkpoint was manned by Afghan police and several of their German military-police trainers. Germans in a Dingo armoured car opened fire at the moving car from a distance of about 100 metres.