At least eight people were killed and over 300 injured after a panic during the sold-out Astroworld music festival in the US city of Houston on Friday, the fire chief said.

More than 300 people were treated at an on-site field hospital and 23 were transported to hospitals, including 17 who were taken after the crush, Houston officials said. Eleven people who were transported by ambulance to hospitals were in cardiac arrest.

Around 9:15 pm US time "the crowd began to compress toward the front of the stage," Fire Chief Samuel Peña said at a news conference early Saturday. "That caused some panic, and it started causing some injuries, people began to fall out, become unconscious, and it created additional panic," the fire chief said

About 50,000 people were at the event at NRG Park, which was being put on by rapper and producer Travis Scott and kicked off Friday. The festival is in its third year.
Earlier, there were injuries after people rushed a front entrance, NBC affiliate KPRC of Houston reported.

"Our hearts are broken," Harris County Judge Lina Hidalgo said. "People go to these events looking for a good time, a chance to unwind, a chance to make memories."