British Airways jets in South Africa have been grounded “indefinitely” by the country’s aviation regulator over fears of engine failures and landing gear malfunctions.

Comair, which runs British Airways-branded services across southern Africa, has been suspended from flying since Saturday.

The South African Civil Aviation Authority extended a temporary ban to an indefinite one a day later.

The regulator said: “Comair operations experienced occurrences ranging from engine failures, engine malfunction and landing gear malfunctions, amongst others.”

In the “interests of safety” officials had to investigate the problems and give Comair the chance to respond to questions.

The airline said it had responded to the queries. The chief executive, Glenn Orsmond, said: “We have since received an acknowledgment that the information has been received, but no other formal communication has been received to date.

“This is a huge blow to our customers, employees and the flying public as it effectively takes 40pc of the capacity out of the market. The implications for the aviation sector and the country are considerable should the suspension continue for any length of time.”

Comair is South Africa’s largest regional carrier with a fleet of 26 Boeing jets, mostly 737-800s. It runs services to 10 destinations on behalf of British Airways, which also include Zimbabwe, Zambia and Namibia and Mauritius. It also operates under another brand, Kulula.

The carrier has been forced to cancel flights, leaving passengers stranded.

Mr Orsmond said: “Our priority now is to assist passengers who have been stranded. We have chartered two aircraft to assist vulnerable passengers and those who most urgently need to travel.”

British Airways declined to comment.