South African airline group Comair Ltd. resumed flights after being given the all clear by the country’s Civil Aviation Authority, which was investigating a series of incidents over concerns about safety.

The decision allows the local operator of British Airways and owner of the low-cost Kulula carrier to restart services on Thursday after a five-day grounding, restoring about 40% of South Africa’s air capacity, Comair said in a statement. 

“We’re ramping up our schedule and should have our regional and domestic services restored by tomorrow, ahead of the long weekend,” Chief Executive Officer Glenn Orsmond said. Monday is a public holiday in South Africa.

The episode wreaked havoc at major airports in Johannesburg and Cape Town as passengers scrambled for limited alternative flights as ticket prices began to soar. Orsmond faced calls to resign from the National Union of Metalworkers of South Africa, which held protests outside the company’s head office.

Numsa reiterated calls for Orsmond to be removed after services were resumed, saying his “extreme cost-cutting measures” were behind the crisis.

The CAA concluded an evaluation of evidence provided by Comair regarding the safety concerns on Wednesday evening, according to a separate statement. While details of the events that led to the suspension haven’t been disclosed, local media such as News24 have reported of incidents such as a British Airways flight making an emergency landing after the landing gear failed to retract.

Comair operates a fleet of 26 Boeing Co. jets, mostly 737-800s, according to the website. The airline went into administration during the Covid-19 crisis, which grounded much of the world’s aircraft fleet.