UDPATE: (CNN)An armed assailant who attacked a German cinema Thursday has been killed, a German official said.
The masked attacker entered the cinema with a rifle shortly before 3 p.m. local time, Hesse Interior Minister Peter Beuth said. The incident took place in Viernheim, near Frankfurt in western Germany.
An early report from German public TV said 25 people were injured in the incident. But it's not clear if any of the injured were shot, or were hurt in other ways.
Beuth said police received a report about four shots fired.
"There were hostages in the vicinity of the individual. It was at this point that he was fatally shot by special forces," he said. "I have no knowledge that anyone else was harmed."
The U.S. Embassy in Germany said officials are looking into the possibility that tear gas might have caused some of the injuries among the people who were hurt, spokeswoman Jackie McKennan said.
The cinema is part of a major shopping center, home to more than 100 businesses. The Rhein Neckar Zentrum Vienheim shopping complex hosts 20,000 visitors daily, according to its website.
"This (police) operation is now finished," the shopping center said on its Facebook page. "At this moment in time we have no information on injured persons. The driveway is still blocked. We will keep you updated on new developments. "
While the motive for Thursday's attack remains unclear, police have repeatedly warned that Germany could be targeted by ISIS.
Germany absorbed more than 1 million refugees last year, and there have been concerns about the possibility of ISIS cells in the country.
ORIGINAL : (CNN) A mass shooting at a cinema in Viernheim, Germany, has left at least 25 people injured, German public TV reported Thursday.
Viernheim is in western Germany, near Frankfurt.
The shooter entered the cinema, apparently heavily armed, around 3 p.m. local time, authorities said.
"We don't know who the shooter is or what kind of weapons he has, but the possibility this could be a terror attack is crossing the minds of people here in Germany," CNN's Atika Shubert reported from Berlin.
It's not clear how many of the injured were shot, and how many may have been hurt in other ways.
The cinema is part of a major shopping center, home to more than 100 businesses. The complex hosts 20,000 visitors daily, according to its website.
Mass shootings are rare in Germany. But in 2002, a gunman opened fire at a high school in Erfurt, killing 16 people -- 13 staff members, two students and a police officer. In 2009, a gunman dressed in military gear killed 15 people in a spree that started at a school and spanned two small towns near Stuttgart.