A masked gunman barricaded himself in a German multiplex cinema with dozens of people on Thursday before being killed by police on high security alert following a string of attacks around Europe, officials said.

No one else was injured at the complex in the western town of Viernheim, 75 kilometers south of Frankfurt, the interior minister of Hesse state, Peter Beuth, said.

"There were hostages inside and there was a struggle (with police) until in the end he was dead."

Security sources quoted by German news agency DPA said there was "no link to terrorism", after deadly attacks in cities including Paris, Brussels and Istanbul that have left European authorities on edge.

Police said the attacker was seen carrying a bag.

Access to the cinema was sealed off for several hours as police searched for possible explosives but the local Mannheimer Morgen newspaper quoted the police later as saying no explosives were found.

Authorities said they had no information on the man's identity or motive. Media reports said the gunman was seen entering the building with "an ammunition belt" draped over his shoulder.

A spokeswoman for the police in nearby Darmstadt said they were investigating what type of weapon the assailant used, adding that it was possible it fired blanks.

Small, youthful-looking

Huri Blakaj, 21, was behind the counter in the ticket office when he saw the man, whom he described as small and youthful-looking, heading toward him. Blakaj hit a panic button located under the cash register.

"He pointed his gun at me," said a visibly shaken Blakaj.

The assailant, who spoke in German without a distinguishable accent, told the other cashiers to lie on the ground while ordering Blakaj to close the door to the building. When Blakaj asked him whether he wanted money, the man replied "no", he recounted.

Shortly afterward, Blakaj said, he heard a volley of gunfire that lasted "around 20 seconds".

Mass shootings are relatively rare in Germany where gun ownership is prevalent but firearm sales and storage are subject to strict regulation.

In the worse case in recent years, 17-year-old Tim Kretschmer went on a rampage with his father's gun at his former school in 2009, killing 15 people before turning the weapon on himself.

AFP - AP

German police officers stand outside a cinema during a rescue operation in Viernheim on Thursday. Boris Roessler / DPA via AP