A driver lost control of their car during a drag racing event in Texas, slamming into a crowd of spectators and killing two children aged six and eight, authorities have said.

The two boys who were killed have not been identified. Alongside them, eight other spectators were injured and taken to hospital, including a 46-year-old woman who is in a critical condition.

The majority of the other injured people are not believed to have sustained life-threatening injuries, although the condition of a 26-year-old man remains unknown.

Two younger children, one aged four and one three months old, were taken to hospital for precautionary evaluations after the crash.

The incident took place at an event called “Airport Race Wars 2” which was being held on a runway at the Kerrville-Kerr County Airport, about 60 miles (97km) northwest of San Antonio.

The event was promoted as an “action packed, family-friendly day” where spectators could watch the “fastest drag cars compete for over $8000 (£5,800) in total prizes.”

Kerrville police said that one of the drivers “lost control and left the runway, crashing into parked vehicles and striking spectators who were observing the races”.

Although the length of the course (an eighth of a mile or 0.2km) was lined with water-filled plastic barriers, these didn’t extend past the finishing line meaning spectators were unprotected as cars decelerated at the end of the race.

The Associated Press cited freelance journalist Louis Amestoy, who was at the event, estimating upward of 3,500 people were in attendance.

He said that spectators could get within 15 feet (4.6m) of the track and many were watching the races from lawn chairs as there were no stands.

Organisers had reminded the attendees to stay in the grass and away from the asphalt, Mr Amestoy said, adding that the driver was nearing the end of the strip when their car veered off course.