A gunman injured several people in a shooting inside a lecture hall at Heidelberg University in southwestern Germany, police said, adding that the perpetrator was now dead.

"A lone perpetrator injured several people in a lecture hall with a long gun. The perpetrator is dead," Mannheim police said in a statement. 

A major police operation was underway at the university's Neuenheimer Feld campus, they added on Twitter, urging people to steer clear of the area "so that rescue workers and emergency services can travel freely."

German daily newspaper Bild reported that the shooter opened fire in the lecture hall injured several people before turning his weapon on himself, although at the time of writing, this had not been confirmed by police.

Heidelberg is a picturesque university town in Baden-Wuerttemberg, home to a population of around 160,000 people. Germany has been hit in recent years by a spate of attacks perpetrated mainly by jihadists or far-right militants.

However, school shootings are relatively rare in Germany, a country with some of the strictest gun laws in Europe.

In 2009, a former pupil killed nine students, three teachers, and three passers-by in a school shooting at Winnenden, also in Baden-Wuerttemberg. The gunman then killed himself.

In 2002, a 19-year-old former student, apparently as revenge for having been expelled, gunned down 16 people, including 12 teachers and two students, at a school in the central German city of Erfurt. He too, then killed himself.