BERLIN (Reuters) -German police arrested four stateless Syrian Palestinians and a Syrian national suspected of committing crimes against humanity and war crimes in Syria about a decade ago, prosecutors said in a statement on Wednesday.

The men, identified in line with German privacy laws only as Jihad A., Mahmoud A., Sameer S. and Wael S., are suspected to have been affiliated with the Free Palestine Movement militia in Syria. Mazhar J. is suspected to have been a Syrian intelligence officer, the statement said.

"The individuals ... are strongly suspected of killing and attempting to kill civilians, (which) qualified as crimes against humanity and war crimes," it said.

Jihad A., Mazhar J. and Sameer S. were arrested in Berlin, Mahmoud A. in Frankenthal in the southwestern German state of Rhineland-Palatinate and Wael S. in the northeastern state of Mecklenburg Vorpommern, prosecutors said.

The individuals are suspected of participating in a violent crackdown on a peaceful anti-government protest in the Al Yarmouk refugee camp in July 2012, in the early stages of Syria's civil war, in which civilian protesters were targeted and shot at. Six individuals died and others were seriously injured, the prosecutors' statement said.

The suspected militia members are also accused of punching and kicking civilians between 2012 and 2014 at checkpoints and beating them with rifle butts, according to prosecutors.

One person was handed over to the Syrian Military Intelligence Service to be imprisoned and tortured, they said. In addition, one of those arrested is suspected of having turned into authorities three people later killed in a mass execution of 41 civilians in April 2013.

The arrests were made thanks to Germany's universal jurisdiction laws, which allow courts to prosecute crimes against humanity committed anywhere in the world.

German authorities coordinated with Sweden in a joint investigation. The Swedish Prosecution Authority said in a separate statement it had arrested three people in Sweden for crimes against international law committed in Syria in 2012.

Anwar al-Bunni, a lawyer helping prosecute Syrians in Germany suspected of war crimes, said the Syrian Center for Studies and Legal Research had been working on this case for three years.

"We had hoped that the main case would focus on the siege of Al Yarmouk camp and the starvation of the people there as a crime against humanity so we could prosecute more suspects, but unfortunately, it was not possible legally," al-Bunni said.

He said the investigation could be expanded to include suspects in other European countries.

Yarmouk, once Syria's largest camp for Palestinian refugees, became a symbol of the grave plight of people in rebel-held territory when it was besieged by Syrian government forces from 2013 until 2018, when it was recaptured from Islamist militants.

(Reporting by Madeline Chambers and Riham Alkousaa; additional reporting by Niklas Pollard in Stockholm; editing by David Holmes and Mark Heinrich)

By Madeline Chambers and Riham Alkousaa