At least eight people have been killed in an apparent trampling during the first night of a music festival in the US state of Texas, an emergency response official has said.

The fire chief of the city of Houston confirmed the deaths late on Friday night at the Astroworld Festival. The incident occurred during a performance by rapper Travis Scott, who created and launched the event in 2018.

"We had at least eight confirmed fatalities tonight and scores of individuals that were injured,” Houston fire chief Samuel Pena said, adding the causes of death had not yet been determined.

Pena said the incident occurred when the crowd began to crowd around the stage at about 9:15pm local time (12:15 GMT). People then began to pass out from not being able to breathe.

Officials transported 17 people to the hospital, including 11 who were in cardiac arrest, Pena said. Many people were also treated at the scene at NRG Park, where a field hospital had been set up.

Images on social media showed a heavy emergency personnel presence at the scene.

Police said they were reviewing video footage of the arena.

The sold-out event was meant to run for two nights, and featured acts such as Drake, Young Thug, Tame Impala, and Earth, Wind and Fire. The second day was cancelled following the deaths.

Authorities said a reunification centre had been set up at a nearby hotel for those who have not heard from loved ones following the incident.

Earlier in the day, crowds at the festival had rushed to a VIP area, knocking over fences and reportedly trampling some people who fell but no serious injuries were reported at the time.

About 50,000 people were in attendance at the festival.