At leat 15 people were killed yesterday when a wave of panic swept through a Love Parade techno street party in the German city of Duisburg, police said.

Another 100 people were lightly injured in the incident, which took place inside a tunnel, the police said.

Organisers said 1.4 million people had turned out for the day-long open-air festival in the city north of Dusseldorf, with most of them unaware of the incident, the NTV television network reported.

Fearing further mass panic, officials in Duisburg opted against an immediate evacuation of the festival grounds where tens of thousands of revellers were still gathered late in the afternoon, a city spokesman said.

Television footage showed emergency personnel working frantically at the tunnel. Dozens of ambulances and emergency vehicles were parked nearby, while medical tents had been set up.

Several helicopters had landed on an elevated road bridge near the scene, which police had closed off with bollards.

First held in Berlin in 1989, the Love Parade is one of the biggest techno festivals in Europe.

It moved from Berlin from 2007 onwards after disagreements with the city authorities over logistics and security and has been held in several other German cities in recent years.

Deadly stampedes of this kind are rare in Europe but have happened elsewhere in the world in recent years.

In May 2009, 11 people were killed, most of them women and children, in a stampede at a world music festival in the Moroccan capital Rabat, which featured pop stars such as Kylie Minogue.