German prosecutors say a 20-year-old German citizen has been arrested and his apartment in the Frankfurt area was searched in connection on suspicion that he committed war crimes in Syria.

The federal prosecutor's office said in a statement Wednesday that the accused, whose name was only given as Aria L., is suspected of having posed next to two severed heads spiked on sticks while he was fighting in the Syrian civil war with a rebel group against President Bashar Assad's army. The statement said the incident happened between March and April 2014.

The prosecutors say the photos of the accused with the two heads were accessible to a broad public via social media.