One of the two brothers died in a suicide bombing in April, the magazine 'Dabiq' reports.
Known within the organisation as Abu Mus'ab al-Almani - father of Mus'ab, the German - the 25-year-old is reported to have driven a truck containing seven tonnes of explosives into the headquarters of the 4th Regiment of the Iraqi army in Wilayat Shamal, northwest of Baghdad.
The other brother also died in a suicide attack, reports the magazine.
The brothers converted to Islam recently, reports WAZ. It is unclear when they travelled to Syria or whether the German authorities had been keeping tabs on them.
