CAIRO — Human remains retrieved from the crash site of EgyptAir Flight 804 have burn marks and are very small in size, suggesting an explosion on board may have downed the aircraft in the east Mediterranean, a senior Egyptian forensics official said Tuesday.

“The logical explanation is that an explosion brought it down,” the official told The Associated Press.

The official, who is part of the Egyptian team investigating the crash that killed all 66 people on board the flight from Paris to Cairo early last Thursday, has personally examined the remains at a Cairo morgue. He spoke on condition of anonymity because he was not authorized to release the information.

However, the head of the government’s forensic agency later Tuesday dismissed as speculation all media reports about human remains from the crash indicating an explosion.

“Whatever has been published is baseless and mere assumptions,” Hisham Abdel-Hamid told Egypt’s state MENA news agency.

A statement from the government’s investigative committee also warned media outlets to be cautious about what is published “to avoid chaos and spreading false rumors and damaging the state’s high interests and national security.”

The Egyptian expert told the AP that all 80 pieces that have been brought to Cairo so far are very small. “There isn’t even a whole body part, like an arm or a head,” said the official, adding that one piece was the left part of a head.