Fearing further panic, Germany's Love Parade continued Saturday, after a panicked stampede of festival-goers left at least 18 dead and dozens injured.

The crush occurred when organizers tried to prevent thousands of people from entering the already-overcrowded parade grounds in Duisburg, near Duesseldorf.

Describing the situation as "very chaotic," police commissioner Juergen Kieskemper said the panic ensued sometime after an announcement warning the incoming crowds to turn around.

Despite the warning, crowds continued to stream into the single wide 500- to 600-metre long tunnel leading to the grounds.

"At some point the column (of people) got stuck, probably because everything was closed up front, and we saw that the first people were already lying on the ground," eyewitness Udo Sandhoefer told n-tv television.

"Others climbed up the walls and tried somehow to get into the grounds from the side, and the people in the crowd that moved up simply ran over those who were lying on the ground."

According to Wolfgang Rabe, the head of the crisis unit set up by Duisburg city authorities, the panic might actually have been triggered outside the tunnel when some revelers tried to leap over a barricade and fell.

Whatever the cause, the aftermath was one of utter chaos, the ground littered with bodies and people milling around.

Stymied by the crowds and the tight confines of the tunnel, emergency workers had trouble reaching the victims. Local cellular telephone service was temporarily disabled as people tried to contact loved ones. Rescue helicopters even had trouble accessing the injured, as there was little room to land.

In the hours following the tragedy, authorities said some or most of the victims were crushed to death. Others may have been killed or injured as they tried to jump barriers and fell several metres.

"The young people came to celebrate and instead there are dead and injured," German Chancellor Angela Merkel said Saturday. "I am horrified by the suffering and the pain."

German media reported the nearby parade grounds were already packed with as many as 1.4 million techno music fans who continued to party, unaware of the tragedy nearby.

Duisberg spokesperson Frank Kopatschek said city officials held an emergency meeting to consider canceling the festivities. In the interest of avoiding a mass panic they decided to allow the parade to continue.

"The crisis meeting determined not to stop the event because at the moment there are too many people on the grounds," Kopatschek told The Associated Press.

The event nevertheless marked the tragedy, turning its website black Saturday night, to showcase a sombre message.

"Our wish to arrange a happy togetherness was overshadowed by the tragic accidents today. ... Our sincere condolences to all the relatives and our thoughts are with all of those who are currently being taken care of."

Since its origins in Berlin, the Love Parade grew from a small peace demonstration in 1989, to a massive celebration of 1.5 million people in 1999.

Following differences with city officials, organizers moved the huge outdoor celebration of electronic dance music and culture to the industrial Ruhr region of western Germany in 2007.

With files from CTV News and The Associated Press