In total 3 men, two of them suspected former members of al-Nusra Front, were arrested in the German city of Dusseldorf
German police on Thursday arrested two Syrians and a Bosnian for alleged offences in militant groups active in war-torn Syria, including the execution of three dozen civilians.
A 35-year-old Syrian identified as Abdalfatah HA is a suspected member of al-Nusra Front - now rebranded as Jabhat Fateh al-Sham.
He is accused of 36 counts of war crimes for allegedly participating in the mass killing of Syrian government employees in 2013, federal prosecutors said in a statement.
German daily Der Spiegel reported that the man was arrested in Düsseldorf.
The other Syrian, Abdulrahman AA, aged 26, is allegedly a member of the same group, and is accused of managing one of its combat unit's funds, vehicles and weapons.
The men were detained by police in the western states of Baden-Wuerttemberg and North Rhine-Westphalia, who also searched their apartments.
Separately, the southern state of Bavaria announced the arrest of a 33-year-old Bosnian who is believed to have supplied the Sunni militia group Jund al-Sham with several vehicles.
German federal prosecutors have launched around a dozen investigations concerning alleged war crimes committed in Syria or Iraq, alongside dozens of cases of suspected membership of militant groups.
The investigations have gained momentum following the arrival of over a million asylum seekers since 2015, including hundreds of thousands of people from Syria and Iraq.
Last July, in the first such conviction in Germany, a German militant was sentenced to two years in prison on war crimes charges after posing for pictures in Syria with the severed and impaled heads of two government troops.
Human rights organisations have long pushed for governments to bring people suspected of war crimes and crimes against humanity in Syria to trial.
The European Centre for Constitutional and Human Rights (ECCHR) said on Thursday it had helped submit the first criminal complaint in Germany against six high-level Syrian military intelligence officials, with the aim that German federal prosecutors should take up the case under the principle of universal jurisdiction.
The ECCHR complaint was filed together with seven Syrian torture survivors and two Syrian lawyers, according to Associated Press.
"In Syria there is total impunity, which produces further violence. Without justice there will be no political solution to the conflict," Mazen Darwish, one of the Syrian lawyers, was quoted as saying in a statement.