A building crane collapsed Wednesday onto a supermarket in western Germany, killing one person and injuring at least five others, police said.

Rescuers were struggling to comb through the wreckage of the Aldi supermarket in the town of Bad Homburg, near Frankfurt, because parts of the building remained at risk of collapse, police said in a statement.

"It can't be ruled out that more people are (trapped) in that area," the statement said. Two of the injured were reported to be in serious condition.

The crane fell onto the checkout area of the Aldi supermarket shortly before noon, Bad Homburg police spokesman Siegfried Schlott told The Associated Press.

It had been stationed at a construction site next door.

The accident occurred around 11:30 a.m. local time. Some 30 shoppers were inside the building, local media reports said. The injured included shoppers, supermarket employees and the crane operator who fell onto the roof which partly collapsed.

Local media also said that the roof was mostly damaged in the cash registers' area where one or several people are thought to be trapped.  

Firefighters at the scene were trying to remove the crane with heavy equipment while attempting to stabilize the damaged roof, media reports said.

With files from Reuters