BERLIN, June 24 (Xinhua) -- At least five people were injured in an explosion in a residential building in the western German city of Wuppertal on late Saturday night, local media reported.

Shortly before Saturday midnight, a huge bang had ripped people in Wuppertal from sleep. The detonation had blown away large parts of the house with three floors and an attic, and a short time later meter-high flames hit the rubble, according to the Focus Online.

The flames blazed in several floors. Even residents of neighboring houses ran into the open after the explosion. Others were cut off the escape route through the staircase and called out of the windows for help. The rescuers took the trapped people to safety via aerial ladders.

The Das Bild quoted a police spokesman on Sunday morning as saying that at least five people have been injured in the incident, several of them seriously.

An earlier report by emergency services said 24 people were injured, according to Das Bild.

The fire brigade was on site with a large contingent of emergency services. Again and again reinforcement was requested. Extinguishing work was in progress until morning, because there were always fires that could only be fought from the outside.

A police spokesperson told the Focus Online Sunday morning that the cause of the explosion is still completely unclear.?