A female security guard at the Ultra Music Festival in Miami, Florida is in critical condition after she was trampled by a mob of fans who stormed the venue without tickets.

Contemporary Services Corporation guard Erica MACk, 28, was admitted to Jackson Memorial Hospital on Friday night (28Mar14) after party crashers toppled a gate at the perimeter of the Bayfront Park gig to gain access to the electronic music bash, which featured sets by Tiesto, Kaskade, Mgmt and M.I.A., among others.

The victim suffered severe brain haemorrhaging and a broken leg, and is currently in a critical but stable condition.

Miami Police Lieutenant Ignatius Carroll says, "A mob of people came and started rushing the gate and started pushing it. She was doing what she was supposed to do, telling them to stop, when they pushed it down and it fell on top of her... They just trampled her."

Cops from the city's homicide unit are investigating the gate crash and are seeking witnesses to the incident.

The horrific stampede has prompted Miami Mayor Tomas Regalado to condemn the festival's organisers for failing to ensure the fencing was secure, insisting they "acted irresponsibly" as they had apparently ignored earlier advice from officers who had inspected the perimeter and told them to put up additional gates in the area where MACk was trampled.

Regalado has also cast doubt on allowing future Ultra festivals to be staged in Miami, stating, "I think we should not have Ultra next year here. This incident should never have happened."

The gate collapse wasn't the only incident to mar Friday night's festivities - police arrested a total of 22 people on the first night of the three-day event, 15 of them on felony charges, although details about the counts have not been released.

Another 26 people were arrested on Saturday (29Mar14).