A 17-year-old girl has become the fourth person to die after earlier being crushed at a Halloween party in Madrid, Spanish hospital officials say.
The stampede happened in the early hours of Thursday morning in a passageway within the venue leading to the central concert area at Madrid Arena, where the disco-style party with American DJ Steve Aoki was under way.
The 17-year-old's parents, who were on a trip to Brazil when the disaster happened, rushed to the hospital on Friday afternoon after landing landing Madrid, but she died on Saturday morning.
The three other women killed in the stampede were all aged 18, while a 20-year-old woman remains in a serious but stable condition in hospital.
Spanish police are investigating security camera footage in a corridor of the Madrid Arena to establish what sparked the crush.
It's thought lighted firecrackers and a flare panicked the crowd when they were thrown among them.
Madrid's deputy mayor Miguel Angel Villanueva said the venue's maximum capacity of 10600 people had not been exceeded and 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.
Aoki said he was "devastated" to hear about the deaths and cancelled a planned show in the northern city of Bilbao on Thursday night "out of respect for those who lost their lives and those who are injured".
He said: "The safety of my fans has always been my top priority and had I known that there was any distress putting people in jeopardy within the venue I would have ended my show immediately."