Terror experts have more reasons to suspect that the Islamic State (ISIS) may have planted a bomb in the doomed Russian plane that crashed in Egypt Saturday, killing 224 people, including 17 children.

The Daily Express reported that the Airbus A321 of the Metrojet charter flight broke up in mid-air and the pilot didn't make a distress call, which means a mechanical failure was least likely to have caused the disaster. Debris were also scattered on the dessert, which suggests that there was a major explosion. Experts also found out that the jet's skin peeled outwards, which means there was a force from the inside that caused the plane to crash. The airline earlier ruled out pilot error.

However, The Guardian reported that there was a group claiming to be ISIS who posted online that they brought down a plane above Sinai province. However, Russian transport minister Maksim Sokolov said the claim isnt accurate. Egypt's army spokesperson Mohamed Samir also negated the claim. 

According to USA Today, Russia's air transport chief Alexander Neradko said the plane crashed in the Sinai Peninsula in Egypt. The debris scattered over 6 square miles of Dessert, which means it broke down in midair while at a high altitude.

The jet was en route from the Sharm El-Sheikh at the Red Sea in Egypt headed to St. Petersburg, Russia. It disappeared from the radar 23 minutes after its flight. Meanwhile, an Egyptian civil aviation ministry official said that the plane could have been brought down by an explosive that was planted onboard.

However, Egypt's civil aviation minister Hossam Kamal said, "Up until the crash happened, we were never informed of any faults in the plane, nor did we receive any SOS calls."

Egypt's president Abdel Fattah said it's too soon to determine the cause of the crash and it requires an extensive, complicated technical study. These statements come right after ISIS militants posted videos online showing the plane breaking up while it is 31,000 feet up in the air.