Germany's intelligence service believes Islamic State jihadist fighters in northern Iraq possess anti-aircraft weapons that could take down passenger jets, according to a newspaper report Sunday.

The BND federal intelligence service had told German lawmakers about its suspicion in a confidential briefing late last week, reported the Bild am Sonntag newspaper without citing named sources.

In the briefing, the BND reportedly warned that IS fighters possess portable rocket launchers captured from Syrian army stocks. Some dated from the 1970s, while others were modern and advanced.

The shoulder-mounted rocket launchers -- known as Man Portable Air Defense Systems or MANPADS -- were of Russian design but may have been manufactured in other countries including Bulgaria or China, the report said.

German police injured in clashes with far-right protesters
Berlin (AFP) Oct 26, 2014 - At least 13 German riot police were injured Sunday in clashes with far-right hooligans rallying against Islamist extremism in the western city of Cologne, a police spokesman told SID agency, an AFP subsidiary.

Six people were arrested and one of the police officers was seriously hurt, the spokesman told the German sports news agency.

Police used batons, pepper spray and water cannon against the protesters, who hurled rocks, bottles and firecrackers at them, he said.

Around 2,500 hardline football fans and far right extremists from across Germany had massed under the banner "Hooligans against Salafists", drawing some 500 leftist and anti-fascist counter protesters.

Tensions escalated and right-wing protesters repeatedly yelled "Foreigners out!", reported national news agency DPA and witnesses using Twitter.

Earlier this month Kurds in Germany clashed with radical Muslims in the northern city of Hamburg and elsewhere, in street protests fuelled by the conflict involving the jihadist group Islamic State in northern Iraq and Syria.