Fire swept through a passenger bus in Zimbabwe, killing more than 40 people and injuring at least 20, some of whom suffered severe burns, authorities said Friday.A photograph posted on Twitter by the Zimbabwe Red Cross shows the remains of the bus that was completely incinerated late on Thursday. The Red Cross said its teams responded to a "horrific accident" involving a bus heading to neighboring South Africa at around midnight."Combustible material was allowed onto the bus, thus causing a conflagration which entrapped, scalded and consumed innocent passengers," President Emmerson Mnangagwa said in a condolence message.Mnangagwa said the government should "take appropriate measures which comprehensively deal with this growing menace on our roads."The accident happened in Gwanda district, about 550km south of Harare, Zimbabwe's capital.Police spokeswoman Charity Charamba confirmed a death toll of more than 40.Last week, a collision between two buses in Zimbabwe killed 50 people and injured about 80.I was devastated to learn of last night’s tragedy, the second major accident in recent weeks. The thoughts and prayers of a grieving nation go out to the wounded and the families of those killed. We will ensure they get the care and support they require. (1/2)— President of Zimbabwe (@edmnangagwa) November 16, 2018As the police investigate the circumstances that led to this tragedy, I urge all my fellow citizens to be extra cautious on the roads – check the safety of your vehicles, slow down, put safety first. We all have a role to play in saving lives and making Zimbabwe a safer country.— President of Zimbabwe (@edmnangagwa) November 16, 2018* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.