JOHANNESBURG (AP) — A pregame stunt involving two passenger jets flying dramatically low over a sports stadium in South Africa drew huge cheers from the estimated crowd of around 56,000 people, but also sparked a major debate over safety risks.

The flyby by two Embraer jets operated by local airline Airlink happened on Saturday before a rugby game between South Africa and New Zealand in Cape Town.

Flight tracking service Flightradar24 estimated that the lead jet passed just 41 to 46 feet (12 to 14 meters) above the roof of Cape Town Stadium, with the crowd and the top-ranked rugby teams in the world below.

The second jet, which was right behind, flew through a cloud of pink dust that shot up from the stadium roof as part of the pregame show.

Airlink, a sponsor of the South African rugby team, said that the flyby was conducted according to safety regulations.

The airline said that it was carefully planned and rehearsed, with the aircraft traveling at around 150 knots (278 kph or 172 mph), when they went over the stadium. Each jet had three senior captains onboard, Airlink said, operating in the roles of a commander, a co-pilot and a safety officer.

The jets weren’t carrying any passengers.

“Airlink notes the concerns expressed in various social media and online forums regarding yesterday’s formation flyby over Cape Town’s DHL Stadium,” Airlink said on Sunday. “The flight demanded careful planning and rehearsal, as it required navigating at low altitude, at around 150 knots. The South African Civil Aviation Authority and Air Traffic Navigation Services provided valuable guidance, approval and support to ensure a safe flyby.”

South African rugby has a tradition of stadium flybys at big games, starting when a Boeing 747 flew over another stadium in Johannesburg before the 1995 Rugby World Cup final between the same teams, which are fierce rivals.

But this weekend’s flyby was especially low and dramatic, generating global interest after it was shown as part of the pregame broadcast, and sparking a flurry of videos shot by witnesses.

Some aviation experts questioned whether the margin for error was too small.

“Basically, that lead aircraft … was kind of like dodging over the roof and climbing over the one side and dipping below and then climbing over the other side. That was a little bit uncomfortable,” Chris Martinus, president of Aircraft Owners and Pilots Association South Africa, told The Associated Press on Monday.

He said if “something adverse happens, you just don’t have options at that kind of altitude.”

Keith Tonkin, an Australian aviation consultant and former military and commercial pilot, said Monday that the Embraer passenger jets — which are small to medium jets designed for regional flights — weren’t designed or intended for that kind of low-level operation and warned against the precedent.

“The bigger picture is that a benchmark has been established and others may expect to do something similar, and that’s not going to end well,” Tonkin said. He added that turbulence or a bird strike at such a low altitude could leave the pilots with too little room to maneuver without hitting the stadium.

Airlink said that the flight data recorded by both aircraft confirmed that their flights were performed within civil aviation safety limits for speed and altitude.