"The crew managed to save the majority of the passengers with the help of [UN peacekeepers] before the plane caught fire," said Dirk Cramers, Hewa Bora's marketing director.
He said the crash had killed 21 people and most of the victims were people on the ground.
Congolese and Red Cross officials had initially reported at least 70 dead in the crash.
The Red Cross said 113 people had been wounded and were being treated in local hospitals and clinics.
Lionel Healing, a photographer who had been at the crash site, told Al Jazeera "it's a scene of absolute chaos".
"What I saw was a large amount of dead bodies being pulled from the wreckage," he said.
"Shortly after takeoff the plane plunged onto a row of shops and right onto a main road, running through the centre of town ... There's aviation fuel that's still burning all over a large part of the centre of town," he said.
Julien Mpaluku, the governor of the province, said the airliner faltered after takeoff and plunged into the populated neighbourhood.
"We have already picked up many bodies - dozens of bodies. There are a lot of flames, which makes it difficult to know if the bodies we are picking up are those of passengers of the plane or else passers-by or people that lived in the area where the plane crashed," he said.
Poor safety record
Last week, the European Union added Hewa Bora to its blacklist of airlines banned from flying in the EU.
On Tuesday, Michele Cercone, an EU spokeswoman, said she had no information on Hewa Bora specifically but said that all airlines based in the Democratic Republic of Congo were banned from EU air space.
"That is because there is a general lack of effective control by the civil aviation authorities there to monitor and maintain minimum technical standards," she said.
David Learmount, an aviation expert, told Al Jazeera the DRC's airline safety record was "appalling".
"It is really at the moment the worst country on the planet - by a very big margin - for aviation safety," he said.
He added that developing economies around the world generally had worse safety records while, "serious accidents that kill people have been virtually ruled out" in more developed economies.
Aircraft are used extensively for transport in the DRC, a huge country with few paved roads, with dozens of companies operating mainly old planes.
The International Air Transport Association has included the DRC in a group of several African countries it classed as an "embarrassment" to the industry.