Two firefighters have died after a plane crashed into a fire truck while taking off at Peru's busiest airport. The Latam Airlines plane collided with the truck just before 15:30 (20:30 GMT) on Friday at Jorge Chávez International Airport in the capital, Lima. Video posted on social media shows the plane careering down the runway, catching fire and smoking as it ground to a halt. No passengers or flight crew were killed, the airline said on Twitter. A 31-year-old firefighter is in a critical condition, according to an executive director of the hospital agency EsSalud. Peru's Health Ministry added that 20 passengers are being treated for injuries - two of them are believed to be serious. It remains unclear why the fire truck entered the runway while the plane was taking off, bound for the southern Peruvian city of Juliaca. During a news conference, Latam CEO Manuel Van Oordt said the flight had been cleared for take-off. "We don't know why [the fire truck] was there," he said. "We didn't ask for their services."