A German police officer who received life-threatening injuries during a knife attack on Friday targeting a rally by the anti-Islam right-wing group Pax Europa in the city of Mannheim remains in serious condition, police said on Saturday.

Five participants in the rally were also wounded in the attack and taken to the hospital, with some having to undergo emergency surgery, authorities have said, while the suspected attacker was shot by police.

Arrest warrant issued, suspect's residence searched

Security sources told DPA news agency the assailant had suffered life-threatening injuries, and a police spokesman said on Saturday that the suspect remained unresponsive following surgery and could not be interrogated as to his motive.

"What we are most concerned about is the question of the motive," the criminal investigations office in the state of Baden-Württemberg, where Mannheim is situated, said.

An attempted homicide arrest warrant was issued against the man, identified as a 25-year-old with Afghan citizenship who had been living in Germany since 2014, on Saturday afternoon, according to state prosecutors in Karlsruhe.

Prosecutors said the suspect was married, with two children, and was most recently resident in the town of Heppenheim, just across the state border in the south of Hesse. Investigators searched his residence late on Friday. According to German broadcaster SWR, the man has been in Germany since 2013.

The case has now been taken over by anti-terror investigators.

What do we know now?

The injured police officer was stabbed in the back of the head several times, according to authorities.

Among the other wounded was leading Pax Europa member Michael Stürzenberger, his organization has said. The event was part of his "Open Eyes" tour, which organizers say aimed to warn of the dangers of "political Islam."

Stürzenberger is reportedly out of danger, with the Pax Europa website quoting him as saying that his operation had gone well and giving his best wishes to the injured police officer.

It remains unclear whether other Pax Europa members were injured.

Bavarian security services have accused Stürzenberger of making "Islamophobic statements," and have classed the organization Pax Europa itself as Islamophobic.

tj/wd (dpa, AFP)