Cairo — Egyptian forensic experts have examined human remains retrieved from the site of the EgyptAir Flight 804 crash, officials told news agencies on Tuesday, amid conflicting statements on whether the initial findings suggest an explosion brought down the plane.

Senior forensic officials, speaking to Reuters and the Associated Press on the condition of anonymity, were quoted as saying that the small size of the body parts suggested that some type of explosion tore the plane apart last week over the Mediterranean. All 66 people aboard were killed.

But in a statement carried by state television, the head of Egypt’s forensic authority, Hesham Abdelhamid, called the reports “mere assumptions” that do not reflect any official position from investigators.

A police official close to the investigation said Tuesday that a small number of bags carrying remains had arrived in Cairo and that “nothing indicates yet what the cause of death could be.”

But the official, speaking on the condition of anonymity because he is not authorized to talk to the media, said that some of the bodies had “disintegrated” — suggesting that a blast had occurred.

The conflicting remarks underscore the pressures facing Egyptian authorities after the crash last Thursday of the Paris-to-Cairo plane. Officials say all theories remain on the table, but speculation has increasingly focused on the possibility of a terrorist attack.

Such a conclusion by investigators would mark another major blow to Egypt’s battle against militants — including factions linked to the Islamic State — and to the nation’s struggling tourism industry, a critical source of revenue.

The pieces of bodies recovered are small, a senior official told the AP, indicating that a blast probably tore apart the aircraft, scattering passengers and wreckage. However, no traces of explosives have been detected on the body parts, Reuters reported.

More than 20 bags of remains, including 80 pieces, have been retrieved, the agencies reported.

Egypt’s civil aviation minister, Sherif Fathy, said last week that terrorism is more likely to have brought down the Airbus A320 than mechanical failure.

According to The Associated Press, a report published by an organization affiliated with Egypt’s Ministry of Civil Aviation notes that the same plane had made an emergency landing in 2013 after one of its engines overheated.

Flight 804 had been en route from Paris to Cairo when it disappeared from radar screens over the Mediterranean Sea about 2:30 a.m. Thursday. Automated messages sent from the aircraft in the minutes before the crash said smoke was detected aboard, near the nose of the plane and in one of the bathrooms, French investigators said.

Egyptian President Abdel Fatah al-Sissi said this week that “all scenarios” are being considered in the investigation. The plane was said to have made abrupt turns before plummeting from its cruising altitude of 37,000 feet, according to Greek officials involved in the investigation.

The airliner’s last contact was with Greek air traffic controllers, who said the pilots reported no problem.