Berlin, Germany (CNN) -- The head of the German army has resigned after a news report that he knew civilians could be killed in a September airstrike in Afghanistan, Germany's defense minister told Parliament Thursday.
Gen. Wolfgang Schneiderhan, the army's chief of staff, asked to be relieved of his duties following the report in Germany's Bild newspaper, said German Defense Minister Karl-Theodor zu Guttenberg.
The Sept. 4 NATO airstrike in the northern province of Kunduz killed at least 90 people. The German commander in the area called in the strike after Afghans tried to siphon fuel from two tankers hijacked by the Taliban a day earlier.
The fuel had been earmarked for NATO's International Security Assistance Force (ISAF).
Local Afghan officials said at least half of those killed were civilians, and NATO acknowledged soon afterward that civilians had been killed.
NATO and Afghan officials launched an investigation, the results of which are still classified, ISAF told CNN Thursday.
Bild, which said it had access to confidential documents and posted a video of the airstrike on its Web site, reported that German Colonel Georg Klein was not able to rule out the possibility of civilian victims before he ordered the strike.
Bild said a report dated September 6 -- two days after the strike -- made clear that it was impossible for Klein to verify information his informant had provided before he called in the airstrike.
CNN's Diana Magnay contributed to this report.