Three women have been killed and two others critically injured during a stampede at a massive Halloween dance party in Spain's capital, Madrid, officials say.

Thousands of people were attending the party at Madrid Arena when the stampede occurred before dawn on Thursday, leaving the victims with trauma injuries or breathing and heart failure, emergency services spokesman Fernando Prado said.

The incident happened in a passageway within the venue leading to the central concert area, where the disco-style party with American DJ Steve Aoki was under way.

An unidentified person had set off a flare or a firework, causing the stampede that trampled the five young women, Miguel Angel Villanueva, the deputy mayor, said.

Fernando Prados, duty chief of Madrid emergency services, said five girls between 18 and 25 were in respiratory arrest when emergency services arrived.

"We performed resuscitation on them and we managed to get a pulse for three of them," he said. One of those women, however, died on the way to hospital, he told Cadena Ser radio.

The two others were in "very serious" condition, he added.

One witness said the stampede left partygoers piled atop one another as high as her shoulders.

"I saw a mass of people, screaming `Help, get me out of here," with security guards tugging at them,'' Ana Gomez told state broadcaster TVE. "I remember seeing the face of one young man, and his expression was that of sheer terror".

Villanueva said the venue's maximum capacity of 10,600 people had not been exceeded and that authorities decided not to evacuate the arena when the accident occurred. Most partygoers were not aware of the stampede because it
was confined to the passage, he said.

Halloween has recently become a popular festivity in Spain, coinciding with the traditional feast of All Saints. 

In Germany, 19 people were crushed to death in a stampede and 342 others were injured two years ago at a techno party in Duisburg.

Source: Agencies